概述
本文描述WPF的拖放功能(Drag and Drop)。
拖放功能涉及到两个功能,一个就是拖,一个是放。拖放可以发生在两个控件之间,也可以在一个控件自己内部拖放。假设界面上有两个控件,一个TreeView,一个ListView,那么可能发生的拖动有以下几种情况:
1、TreeView -> ListView
2、ListView -> TreeView
3、TreeView -> TreeView
4、ListView -> ListView
对于拖的控件需要在鼠标移动事件中检测左键按下并启动拖动操作;对于放的控件需要处理Drop等事件来接收数据。如果是在控件内部拖动,则以上两个动作都要处理。
为简便起见,本文就以ListView拖动到TreeView为例进行讲解。
拖
在拖与放的控件之间一定会有数据传递,我们可以设计一个类型来进行数据传输,由于ListView本身就是绑定到一个对象列表的,我就把选中的对象字节拿来传递了,没有额外定义类型。- public class ListViewAdvNodeItem
- {
- public string Title {get;set;}
-
- }
复制代码 listView.ItemsSource的数据类型为:BindableCollection ListViewAdvNodeItems,通过this.listView.SelectedItem可以得到的数据类型即为:ListViewAdvNodeItem
设计代码如下:- <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView>
复制代码 在listView_MouseMove事件中,我们将启动拖动功能。- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> private void listView_MouseMove(object sender, MouseEventArgs e) {
- if (sender is ListView listview
- <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> && e.LeftButton == MouseButtonState.Pressed
- <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> && listview.SelectedItem != null) <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> { <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView>DragDrop.DoDragDrop(listview, listview.SelectedItem, DragDropEffects.Move); <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> } }
复制代码 通过DragDrop.DoDragDrop方法启动拖动,该方法有三个参数:
1、发起拖动的控件
2、传输的数据(这里是一个ListViewAdvNodeItem类型的对象)
3、拖动的类型,一般为Move或Copy
放
下面就要在TreeView控件中处理放的事件了
设计代码:- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
复制代码 首先要设置AllowDrop="True",然后重点处理DragDrop.Drop事件:在处理Drop事件时,我们需要知道两件事情,1:拖来的是什么数据?2、放哪里了?
首先,通过e.Data.GetData(typeof(ListViewAdvNodeItem))就可以获得数据来源,这里GetData得到的对象就是上面的 listview.SelectedItem;
其次,通过e.OriginalSource 我们将获得数据放在哪里的问题。这段代码很难理解,要回头看一下TreeView的ItemTemplate定义从这个模板定义可以看出,TreeView中用来显示Title的控件是一个TextBlock,然后这个TextBlock的Tag属性上还绑定了一个业务对象。
再回头看上面一段代码,就可以看出具体的逻辑:当鼠标放开时,其所指的对象是一个TextBlock,然后取到这个TextBlock的Tag对象,里面包含了我想要的业务数据。
到此拖放功能就完成了。
为了更好的展现效果,我们可以对拖放的目标进行判断,对于一些不能放的位置显示禁止拖放的图标,这时就需要处理DragOver事件了
装饰器
如果拖动时,有下面这样的一个标签跟随鼠标移动,其显示内容是拖动对象的Title,效果就更好了。

这个就需要通过装饰器来实现。
关于装饰器的介绍:装饰器概述 - WPF .NET Framework | Microsoft Docs
首先我们建一个装饰器对象DragTitleAdorner
  - public class DragTitleAdorner : Adorner { private readonly ContentPresenter _contentPresenter; private Control Control { <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> get <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> { <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView>return (Control)this.AdornedElement; <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> } } public DragTitleAdorner(UIElement adornedElement, Point pos, string? Title = "") : base(adornedElement) { <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> IsHitTestVisible = false; <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> int width = 22; <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> if (Title != null) <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> { <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView>width += (int)MeasureTextWidth(Title, 14, "宋体"); <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> } <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> this._contentPresenter = new ContentPresenter <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> { <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView>Content = new Border <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView>{ <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> Background = Brushes.SteelBlue, <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> Width = width, <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> Height = 28, <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> BorderBrush = Brushes.Gray, <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> BorderThickness = new Thickness(1), <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> HorizontalAlignment = HorizontalAlignment.Left, <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> VerticalAlignment = VerticalAlignment.Top, <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> CornerRadius= new CornerRadius(5), <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> Child = new TextBlock <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> { <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> Text = Title, <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> FontSize = 14, <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> FontFamily= new FontFamily("宋体"), <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> Foreground = Brushes.White, <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> HorizontalAlignment = HorizontalAlignment.Left, <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> VerticalAlignment = VerticalAlignment.Center, <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> Margin = new Thickness(10, 0, 0, 0), <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView> }, <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView>}, <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> }; <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> double left = pos.X; <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> double top = pos.Y; <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> this.Margin = new Thickness(left + 5, top + 10, 0, 0); } #region Override protected override int VisualChildrenCount { <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> get <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> { <ListView x:Name="listView" <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView>
- <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Mouse.MouseMove="listView_MouseMove" >
- </ListView>return 1; <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> } } protected override Visual GetVisualChild(int index) // replace the Visual of the TextBox with the visual of the _contentPresenter; { <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> return this._contentPresenter; } protected override Size MeasureOverride(Size constraint) { <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> this._contentPresenter.Measure(this.Control.RenderSize); // delegate the measure override to the ContentPresenter's Measure <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> return this.Control.RenderSize; } protected override Size ArrangeOverride(Size finalSize) { <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> this._contentPresenter.Arrange(new Rect(finalSize)); <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> return finalSize; } #endregion Override private double MeasureTextWidth(string text, double fontSize, string fontFamily) { <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> FormattedText formattedText = new FormattedText( <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> text, <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> System.Globalization.CultureInfo.InvariantCulture, <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> FlowDirection.LeftToRight, <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> new Typeface(fontFamily.ToString()), <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> fontSize, <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> Brushes.Black <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> ); <TreeView x:Name="treeView"
- AllowDrop="True"
- DragDrop.Drop="treeView_Drop"
- DragDrop.DragOver="treeView_DragOver"
- DragDrop.DragEnter="treeView_DragEnter"
- DragDrop.DragLeave="treeView_DragLeave" >
- </TreeView> return formattedText.WidthIncludingTrailingWhitespace; } }
复制代码 View Code在构造这个对象时,我们将传入两个重要的参数:Point pos 和 string Title ,这两个参数决定了它在何处显示什么内容。
程序用代码构建了一个Border,其内有一个TextBlock,并通过pos参数来控制了它的位置。
下面,在treeView_DragOver事件中显示这个装饰器即可。 更多信息请参考文末源码。
资源
系列目录:WPF开发快速入门【0】前言与目录
代码下载:Learn WPF: WPF学习笔记 (gitee.com)
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