论坛 › 移动端开发 › Android studio 编写一个登录页面，并且具有注册功能

守听 发表于 2022-6-26 00:13:36

Android studio 编写一个登录页面，并且具有注册功能

登录与注册



[*]功能要求
[*]具体实现
[*]

[*]初步思路
[*]涉及的代码文件
[*]实现效果

[*]代码文件
[*]

[*]1.登录界面——MainActivity.java ：
[*]2.注册界面——Register.java
[*]3.欢迎界面——Welcome.java
[*]4.数据库——Mysql.java


功能要求

1、创建登录界面，点击注册按钮，弹出注册窗口。
2、创建注册窗口，输入用户名和密码，在SQLite中存储用户名和密码。
3、注册成功，跳转到登录界面，进行登录。
4、注册成功，把用户名和密码保存到SharedPreferences中，登录时自动填充用户名和密码。
具体实现

初步思路

          登录页面具有两个输入框和两个按键，输入框分别用于获取用户名和密码，按键分为登录按键和注册按键，分别跳往不同的页面。登陆成功后，进入到欢迎界面。注册跳转到注册页面，注册成功后，将数据存储到SharedPreferences和数据中，返回登录页面将SharedPreferences中的数据填充到输入框中。
涉及的代码文件


[*]MainActivity.java ：主界面
[*]Mysql.java：利用sqlite的SQLiteOpenHelper类创建数据库
[*]Register.java：注册页面
[*]Welcome.java:登陆成功后的欢迎界面:
[*]activity_main.xml:登录页面的布局文件
[*]activity_register.xml:注册页面的布局文件
[*]activity_welcome.xml:欢迎页面的布局文件
一般在Android studio 中创建Activity都会自动在AndroidManifest.xml中好，本次代码中也不需要对AndroidManifest.xml做任何更改。
实现效果

1登录页面：
       这是我之前注册过后的账户，所以点击进去就自动填充好了信息。
https://img-blog.csdnimg.cn/20210605151502881.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MDEzMjYx,size_2,color_FFFFFF,t_70
2.注册页面：
       注册页面写的非常简略，如果想实现更多的效果可以网上查查，也可以参照下我上一篇文章中的注册页面。
编写一个简单的andriod注册页面，并跳转后显示注册信息
https://img-blog.csdnimg.cn/20210605151857543.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MDEzMjYx,,size_16,color_FFFFFF,t_70
3.注册成功后：
       注册成功后会自动跳转到登录页面，并且填充信息。
https://img-blog.csdnimg.cn/20210605152045580.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MDEzMjYx,size_16,color_FFFFFF,t_70
4.登录成功后：
       登陆成功后会将用户名取出来，并显示欢迎。
https://img-blog.csdnimg.cn/20210605152129123.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ1MDEzMjYx,size_16,color_FFFFFF,t_70
代码文件

1.登录界面——MainActivity.java ：

       这里登录比对数据的时候，我采用的方法是从数据库中查询与输入的用户名、密码相同的记录，若记录存在则登陆成功。不存在则提示用户用户名或密码输入错误。
package com.example.test06;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>EditText name,pwd;
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Button btnlogin,btnreg;
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Mysql mysql;
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>SQLiteDatabase db;
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>SharedPreferences sp1,sp2;
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>@Override
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>protected void onCreate(Bundle savedInstanceState) {
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>super.onCreate(savedInstanceState);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>setContentView(R.layout.activity_main);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>name = this.findViewById(R.id.name);<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//用户名输入框
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>pwd = this.findViewById(R.id.pwd);<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//密码输入框
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>btnlogin = this.findViewById(R.id.login);<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout> //登录按钮
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>btnreg = this.findViewById(R.id.reg);<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>   //注册按钮
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>sp1 =this.getSharedPreferences("useinfo",this.MODE_PRIVATE);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>sp2 = this.getSharedPreferences("username",this.MODE_PRIVATE);

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>name.setText(sp1.getString("usname",null));
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>pwd.setText(sp1.getString("uspwd",null));
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>mysql = new Mysql(this,"Userinfo",null,1);<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//建数据库或者取数据库
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>db = mysql.getReadableDatabase();
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>btnlogin.setOnClickListener(new View.OnClickListener() {<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//登录事件
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>@Override
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>public void onClick(View v) {
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>String username = name.getText().toString();
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>String password = pwd.getText().toString();<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout> //获取用户输入的用户名和密码
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//查询用户名和密码相同的数据
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Cursor cursor = db.query("logins",new String[]{"usname","uspwd"}," usname=? and uspwd=?",new String[]{username,password},null,null,null);

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>int flag = cursor.getCount();<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//查询出来的记录项的条数，若没有该用户则为0条
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>if(flag!=0){<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//若查询出的记录不为0，则进行跳转操作
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Intent intent = new Intent();
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>intent.setClass(MainActivity.this,Welcome.class);<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//设置页面跳转
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>SharedPreferences.Editor editor = sp2.edit();
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>cursor.moveToFirst();<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>   //将光标移动到position为0的位置，默认位置为-1
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>String loginname = cursor.getString(0);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>editor.putString("Loginname",loginname);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>editor.commit();<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//将用户名存到SharedPreferences中
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>startActivity(intent);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>else{
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Toast.makeText(MainActivity.this,"用户名或密码错误！",Toast.LENGTH_LONG).show();<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout> //提示用户信息错误或没有账号
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>});

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>btnreg.setOnClickListener(new View.OnClickListener() {<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//注册事件
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>@Override
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>public void onClick(View v) {

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Intent intent = new Intent();
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>intent.setClass(MainActivity.this,Register.class);<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//跳转到注册页面
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>startActivity(intent);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Toast.makeText(MainActivity.this,"前往注册！",Toast.LENGTH_SHORT).show();
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>});
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}
} 这是对应的布局文件activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>xmlns:app="http://schemas.android.com/apk/res-auto"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>xmlns:tools="http://schemas.android.com/tools"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="match_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="match_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>tools:context=".MainActivity">

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><LinearLayout
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="match_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="match_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:orientation="vertical">
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><LinearLayout
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="match_parent"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_marginTop="10dp"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:orientation="horizontal">
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><TextView
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="0dp"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_weight="0.3"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:gravity="center"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
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      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:textSize="18dp"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:text="用户名:"/>
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><EditText
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:id="@+id/name"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="0dp"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_weight="1"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_marginRight="20dp"/>
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout></LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><LinearLayout
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="match_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_marginTop="10dp"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:orientation="horizontal">
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><TextView
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="0dp"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:gravity="center"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:textSize="18dp"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_weight="0.3"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
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    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
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    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
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</androidx.constraintlayout.widget.ConstraintLayout>android:id="@+id/pwd"
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</androidx.constraintlayout.widget.ConstraintLayout>android:inputType="textPassword"
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</androidx.constraintlayout.widget.ConstraintLayout></LinearLayout>
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><LinearLayout
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="match_parent"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:orientation="horizontal">
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><Button
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:id="@+id/login"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="wrap_content"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_weight="1"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_margin="5dp"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:text="登录"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
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</androidx.constraintlayout.widget.ConstraintLayout>/>
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    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
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      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
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      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><Button
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
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    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
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      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
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    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:id="@+id/reg"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="wrap_content"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
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    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
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    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
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      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
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      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
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    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
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      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_weight="1"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
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    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_margin="5dp"
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<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:text="注册"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>/>
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout></LinearLayout>
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout></LinearLayout>


</androidx.constraintlayout.widget.ConstraintLayout> 2.注册界面——Register.java

       注册时，会先对用户名进行比对，若用户名存在则提醒用户名已存在。设置密码会比对两次输入的密码是否相同，不相同则发出提醒。
package com.example.test06;

import androidx.appcompat.app.AppCompatActivity;

import android.content.ContentValues;
import android.content.Intent;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class Register extends AppCompatActivity {
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>EditText usename,usepwd,usepwd2;
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Button submit;
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Mysql mysql;
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>SQLiteDatabase db;
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>SharedPreferences sp;
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>@Override
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>protected void onCreate(Bundle savedInstanceState) {
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>super.onCreate(savedInstanceState);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>setContentView(R.layout.activity_register);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>usename = this.findViewById(R.id.usename);                        <?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//用户名编辑框
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>usepwd =this.findViewById(R.id.usepwd);                                //设置初始密码编辑框
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>usepwd2 = this.findViewById(R.id.usepwd2);                        <?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//二次输入密码编辑框
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>submit =   this.findViewById(R.id.submit);                                //注册按钮
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>mysql = new Mysql(this,"Userinfo",null,1);<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//建数据库
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>db = mysql.getReadableDatabase();
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>sp = this.getSharedPreferences("useinfo",this.MODE_PRIVATE);


<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>submit.setOnClickListener(new View.OnClickListener() {
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>boolean flag = true;<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//判断用户是否已存在的标志位
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>@Override
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>public void onClick(View v) {
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>String name = usename.getText().toString();                                //用户名
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>String pwd01 = usepwd.getText().toString();                                //密码
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>String pwd02 = usepwd2.getText().toString();                        //二次输入的密码
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>String sex = "";                                                                                //性别
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>if(name.equals("")||pwd01 .equals("")||pwd02.equals("")){
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Toast.makeText(Register.this, "用户名或密码不能为空!！", Toast.LENGTH_LONG).show();
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>else{
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Cursor cursor = db.query("logins",new String[]{"usname"},null,null,null,null,null);

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>while (cursor.moveToNext()){
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>if(cursor.getString(0).equals(name)){
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>flag = false;
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>break;
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>if(flag==true){<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout> //判断用户是否已存在
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>if (pwd01.equals(pwd02)) {                                                                //判断两次输入的密码是否一致，若一致则继续，不一致则提醒密码不一致
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>ContentValues cv = new ContentValues();
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>cv.put("usname",name);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>cv.put("uspwd",pwd01);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>db.insert("logins",null,cv);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>SharedPreferences.Editor editor = sp.edit();
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>editor.putString("usname",name);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>editor.putString("uspwd",pwd01);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>editor.commit();
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Intent intent = new Intent();
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>intent.setClass(Register.this,MainActivity.class);<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>//跳转到登录页面
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>startActivity(intent);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Toast.makeText(Register.this, "注册成功！", Toast.LENGTH_LONG).show();
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>else {
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Toast.makeText(Register.this, "密码不一致！", Toast.LENGTH_LONG).show();                        //提示密码不一致
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>else{
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>Toast.makeText(Register.this, "用户已存在！", Toast.LENGTH_LONG).show();                        //提示密码不一致
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}


<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>});
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}
} 这是对应的布局文件activity_register.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>xmlns:app="http://schemas.android.com/apk/res-auto"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>xmlns:tools="http://schemas.android.com/tools"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="match_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="match_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>tools:context=".Register">
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><LinearLayout
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="match_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="match_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:orientation="vertical">
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><TextView
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="fill_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:text="用户名:" />

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><EditText
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:id="@+id/usename"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="fill_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:text=""
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>/>
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><TextView
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="fill_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:text="密 码:"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>/>

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><EditText
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:id="@+id/usepwd"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="fill_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:inputType="textPassword"

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>/>
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><TextView
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="fill_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:text="确认密码:"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>/>

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><EditText
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:id="@+id/usepwd2"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="fill_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:inputType="textPassword"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>/>
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><Button
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:id="@+id/submit"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_width="fill_parent"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:layout_height="wrap_content"
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>android:text="注册" />
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout></LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout> 3.欢迎界面——Welcome.java

package com.example.test06;

import androidx.appcompat.app.AppCompatActivity;

import android.content.SharedPreferences;
import android.os.Bundle;
import android.widget.TextView;

public class Welcome extends AppCompatActivity {
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>SharedPreferences sp;
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>TextView showhello;
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>@Override
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>protected void onCreate(Bundle savedInstanceState) {
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>super.onCreate(savedInstanceState);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>setContentView(R.layout.activity_welcome);
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>sp = this.getSharedPreferences("username", this.MODE_PRIVATE);//获取sharepreferences
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>showhello = this.findViewById(R.id.mainword);<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>   //显示欢迎

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>showhello.setText("欢迎你！"+sp.getString("Loginname",""));<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout> //获取用户名
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}
} 这是对应的布局文件activity_welcome.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout> 4.数据库——Mysql.java

package com.example.test06;import android.content.Context;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;import androidx.annotation.Nullable;public class Mysql extends SQLiteOpenHelper {<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>public Mysql(@Nullable Context context, @Nullable String name, @Nullable SQLiteDatabase.CursorFactory factory, int version) {<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>super(context, name, factory, version);<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>@Override<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>public void onCreate(SQLiteDatabase db) {<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>String sql = "create table logins(id integer primary key autoincrement,usname text,uspwd text)";<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout><?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>db.execSQL(sql);<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>@Override<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Welcome">
    <TextView
      android:id="@+id/mainword"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:gravity="center"
      android:textSize="22dp"
      tools:ignore="MissingConstraints" />
</androidx.constraintlayout.widget.ConstraintLayout>}}        代码可能有些简陋，考虑也可能没那么全面，但基本的功能还是可以的。暂时没发现什么大的问题。

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