如何在 .NET MAUI 中加载 json 文件？

引言:

按core传统方式添加 AddJsonFile("appsettings.json") 在windows平台和ssr工作正常,但是在 ios 和 android 无法用这种方式,因为资源生成方式不一样. 使用内置资源方式不够灵活而且 ios 平台会提示不能复制 json 文件到目录,于是进行了几天的研究,终于能正确使用了.

资源文件夹

• 官方工程 Resources\Raw\文件夹 AboutAssets.txt 文件说明
  

1. 您希望与应用程序一起部署的任何原始资产都可以放置在此目录（和子目录）。 将资产部署到您的应用程序, 由 `.csproj` 中的以下 `MauiAsset` 构建操作自动处理。
3. <ItemGroup>
4.   <EmbeddedResource Include="appsettings.json" />
5. </ItemGroup><ItemGroup>
6.   <EmbeddedResource Include="appsettings.json" />
7. </ItemGroup> <MauiAsset Include="Resources\Raw\**" LogicalName="%(RecursiveDir)%(Filename)%(Extension)" />
9. 这些文件将与您的包一起部署，并且可以使用 Essentials 访问：
11. <ItemGroup>
12.   <EmbeddedResource Include="appsettings.json" />
13. </ItemGroup><ItemGroup>
14.   <EmbeddedResource Include="appsettings.json" />
15. </ItemGroup>async Task LoadMauiAsset()
16. <ItemGroup>
17.   <EmbeddedResource Include="appsettings.json" />
18. </ItemGroup><ItemGroup>
19.   <EmbeddedResource Include="appsettings.json" />
20. </ItemGroup>{
21. <ItemGroup>
22.   <EmbeddedResource Include="appsettings.json" />
23. </ItemGroup><ItemGroup>
24.   <EmbeddedResource Include="appsettings.json" />
25. </ItemGroup><ItemGroup>
26.   <EmbeddedResource Include="appsettings.json" />
27. </ItemGroup><ItemGroup>
28.   <EmbeddedResource Include="appsettings.json" />
29. </ItemGroup>using var stream = await FileSystem.OpenAppPackageFileAsync("AboutAssets.txt");
30. <ItemGroup>
31.   <EmbeddedResource Include="appsettings.json" />
32. </ItemGroup><ItemGroup>
33.   <EmbeddedResource Include="appsettings.json" />
34. </ItemGroup><ItemGroup>
35.   <EmbeddedResource Include="appsettings.json" />
36. </ItemGroup><ItemGroup>
37.   <EmbeddedResource Include="appsettings.json" />
38. </ItemGroup>using var reader = new StreamReader(stream);
40. <ItemGroup>
41.   <EmbeddedResource Include="appsettings.json" />
42. </ItemGroup><ItemGroup>
43.   <EmbeddedResource Include="appsettings.json" />
44. </ItemGroup><ItemGroup>
45.   <EmbeddedResource Include="appsettings.json" />
46. </ItemGroup><ItemGroup>
47.   <EmbeddedResource Include="appsettings.json" />
48. </ItemGroup>var contents = reader.ReadToEnd();
49. <ItemGroup>
50.   <EmbeddedResource Include="appsettings.json" />
51. </ItemGroup><ItemGroup>
52.   <EmbeddedResource Include="appsettings.json" />
53. </ItemGroup>}

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复制一份txt文件按操作复现成功.

• 直接丢入 appsettings.json 编译到ios平台提示错误不能复制 json 文件到目录, 经google,找到方案,需要项目文件属性中 Remove 文件
  

相关错误提示
The path 'XXXXXXX\appsettings.json' would result in a file outside of the app bundle and cannot be used.
The path '..\..\..\..\..\..\..\Repos\BlazorMaui\BlazorMaui\appsettings.json' would result in a file outside of the app bundle and cannot be used.
最终方案:

• appsettings.json文件直接放工程根目录
  
• 文件属性生成操作为 MauiAsset 和 不复制
  
• 需要在项目属性中 Remove 文件
  

项目文件

1. <ItemGroup>
2.   <EmbeddedResource Include="appsettings.json" />
3. </ItemGroup><ItemGroup>
4.   <EmbeddedResource Include="appsettings.json" />
5. </ItemGroup><ItemGroup>
6. <ItemGroup>
7.   <EmbeddedResource Include="appsettings.json" />
8. </ItemGroup><ItemGroup>
9.   <EmbeddedResource Include="appsettings.json" />
10. </ItemGroup><ItemGroup>
11.   <EmbeddedResource Include="appsettings.json" />
12. </ItemGroup><Content Remove="appsettings.json" />
13. <ItemGroup>
14.   <EmbeddedResource Include="appsettings.json" />
15. </ItemGroup><ItemGroup>
16.   <EmbeddedResource Include="appsettings.json" />
17. </ItemGroup></ItemGroup>
18. <ItemGroup>
19.   <EmbeddedResource Include="appsettings.json" />
20. </ItemGroup><ItemGroup>
21.   <EmbeddedResource Include="appsettings.json" />
22. </ItemGroup>
23. <ItemGroup>
24.   <EmbeddedResource Include="appsettings.json" />
25. </ItemGroup><ItemGroup>
26.   <EmbeddedResource Include="appsettings.json" />
27. </ItemGroup>
28. <ItemGroup>
29.   <EmbeddedResource Include="appsettings.json" />
30. </ItemGroup><ItemGroup>
31.   <EmbeddedResource Include="appsettings.json" />
32. </ItemGroup><ItemGroup>
33. <ItemGroup>
34.   <EmbeddedResource Include="appsettings.json" />
35. </ItemGroup><ItemGroup>
36.   <EmbeddedResource Include="appsettings.json" />
37. </ItemGroup><ItemGroup>
38.   <EmbeddedResource Include="appsettings.json" />
39. </ItemGroup><MauiAsset Include="appsettings.json">
40. <ItemGroup>
41.   <EmbeddedResource Include="appsettings.json" />
42. </ItemGroup><ItemGroup>
43.   <EmbeddedResource Include="appsettings.json" />
44. </ItemGroup><ItemGroup>
45.   <EmbeddedResource Include="appsettings.json" />
46. </ItemGroup><ItemGroup>
47.   <EmbeddedResource Include="appsettings.json" />
48. </ItemGroup><CopyToOutputDirectory>Never</CopyToOutputDirectory>
49. <ItemGroup>
50.   <EmbeddedResource Include="appsettings.json" />
51. </ItemGroup><ItemGroup>
52.   <EmbeddedResource Include="appsettings.json" />
53. </ItemGroup><ItemGroup>
54.   <EmbeddedResource Include="appsettings.json" />
55. </ItemGroup></MauiAsset>
56. <ItemGroup>
57.   <EmbeddedResource Include="appsettings.json" />
58. </ItemGroup><ItemGroup>
59.   <EmbeddedResource Include="appsettings.json" />
60. </ItemGroup></ItemGroup>

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读取配置文件代码

1. <ItemGroup>
2.   <EmbeddedResource Include="appsettings.json" />
3. </ItemGroup><ItemGroup>
4.   <EmbeddedResource Include="appsettings.json" />
5. </ItemGroup><ItemGroup>
6.   <EmbeddedResource Include="appsettings.json" />
7. </ItemGroup><ItemGroup>
8.   <EmbeddedResource Include="appsettings.json" />
9. </ItemGroup>async static Task<Stream> LoadMauiAsset()
10. <ItemGroup>
11.   <EmbeddedResource Include="appsettings.json" />
12. </ItemGroup><ItemGroup>
13.   <EmbeddedResource Include="appsettings.json" />
14. </ItemGroup><ItemGroup>
15.   <EmbeddedResource Include="appsettings.json" />
16. </ItemGroup><ItemGroup>
17.   <EmbeddedResource Include="appsettings.json" />
18. </ItemGroup>{
19. <ItemGroup>
20.   <EmbeddedResource Include="appsettings.json" />
21. </ItemGroup><ItemGroup>
22.   <EmbeddedResource Include="appsettings.json" />
23. </ItemGroup><ItemGroup>
24.   <EmbeddedResource Include="appsettings.json" />
25. </ItemGroup><ItemGroup>
26.   <EmbeddedResource Include="appsettings.json" />
27. </ItemGroup><ItemGroup>
28.   <EmbeddedResource Include="appsettings.json" />
29. </ItemGroup><ItemGroup>
30.   <EmbeddedResource Include="appsettings.json" />
31. </ItemGroup>try
32. <ItemGroup>
33.   <EmbeddedResource Include="appsettings.json" />
34. </ItemGroup><ItemGroup>
35.   <EmbeddedResource Include="appsettings.json" />
36. </ItemGroup><ItemGroup>
37.   <EmbeddedResource Include="appsettings.json" />
38. </ItemGroup><ItemGroup>
39.   <EmbeddedResource Include="appsettings.json" />
40. </ItemGroup><ItemGroup>
41.   <EmbeddedResource Include="appsettings.json" />
42. </ItemGroup><ItemGroup>
43.   <EmbeddedResource Include="appsettings.json" />
44. </ItemGroup>{
46. <ItemGroup>
47.   <EmbeddedResource Include="appsettings.json" />
48. </ItemGroup><ItemGroup>
49.   <EmbeddedResource Include="appsettings.json" />
50. </ItemGroup><ItemGroup>
51.   <EmbeddedResource Include="appsettings.json" />
52. </ItemGroup><ItemGroup>
53.   <EmbeddedResource Include="appsettings.json" />
54. </ItemGroup><ItemGroup>
55.   <EmbeddedResource Include="appsettings.json" />
56. </ItemGroup><ItemGroup>
57.   <EmbeddedResource Include="appsettings.json" />
58. </ItemGroup><ItemGroup>
59.   <EmbeddedResource Include="appsettings.json" />
60. </ItemGroup><ItemGroup>
61.   <EmbeddedResource Include="appsettings.json" />
62. </ItemGroup>using var stream = await FileSystem.OpenAppPackageFileAsync("appsettings.json");
63. <ItemGroup>
64.   <EmbeddedResource Include="appsettings.json" />
65. </ItemGroup><ItemGroup>
66.   <EmbeddedResource Include="appsettings.json" />
67. </ItemGroup><ItemGroup>
68.   <EmbeddedResource Include="appsettings.json" />
69. </ItemGroup><ItemGroup>
70.   <EmbeddedResource Include="appsettings.json" />
71. </ItemGroup><ItemGroup>
72.   <EmbeddedResource Include="appsettings.json" />
73. </ItemGroup><ItemGroup>
74.   <EmbeddedResource Include="appsettings.json" />
75. </ItemGroup><ItemGroup>
76.   <EmbeddedResource Include="appsettings.json" />
77. </ItemGroup><ItemGroup>
78.   <EmbeddedResource Include="appsettings.json" />
79. </ItemGroup>using var reader = new StreamReader(stream);
81. <ItemGroup>
82.   <EmbeddedResource Include="appsettings.json" />
83. </ItemGroup><ItemGroup>
84.   <EmbeddedResource Include="appsettings.json" />
85. </ItemGroup><ItemGroup>
86.   <EmbeddedResource Include="appsettings.json" />
87. </ItemGroup><ItemGroup>
88.   <EmbeddedResource Include="appsettings.json" />
89. </ItemGroup><ItemGroup>
90.   <EmbeddedResource Include="appsettings.json" />
91. </ItemGroup><ItemGroup>
92.   <EmbeddedResource Include="appsettings.json" />
93. </ItemGroup><ItemGroup>
94.   <EmbeddedResource Include="appsettings.json" />
95. </ItemGroup><ItemGroup>
96.   <EmbeddedResource Include="appsettings.json" />
97. </ItemGroup>var contents = reader.ReadToEnd();
98. <ItemGroup>
99.   <EmbeddedResource Include="appsettings.json" />
100. </ItemGroup><ItemGroup>
101.   <EmbeddedResource Include="appsettings.json" />
102. </ItemGroup><ItemGroup>
103.   <EmbeddedResource Include="appsettings.json" />
104. </ItemGroup><ItemGroup>
105.   <EmbeddedResource Include="appsettings.json" />
106. </ItemGroup><ItemGroup>
107.   <EmbeddedResource Include="appsettings.json" />
108. </ItemGroup><ItemGroup>
109.   <EmbeddedResource Include="appsettings.json" />
110. </ItemGroup><ItemGroup>
111.   <EmbeddedResource Include="appsettings.json" />
112. </ItemGroup><ItemGroup>
113.   <EmbeddedResource Include="appsettings.json" />
114. </ItemGroup>Console.WriteLine("OpenAppPackageFileAsync => " + contents);
115. <ItemGroup>
116.   <EmbeddedResource Include="appsettings.json" />
117. </ItemGroup><ItemGroup>
118.   <EmbeddedResource Include="appsettings.json" />
119. </ItemGroup><ItemGroup>
120.   <EmbeddedResource Include="appsettings.json" />
121. </ItemGroup><ItemGroup>
122.   <EmbeddedResource Include="appsettings.json" />
123. </ItemGroup><ItemGroup>
124.   <EmbeddedResource Include="appsettings.json" />
125. </ItemGroup><ItemGroup>
126.   <EmbeddedResource Include="appsettings.json" />
127. </ItemGroup><ItemGroup>
128.   <EmbeddedResource Include="appsettings.json" />
129. </ItemGroup><ItemGroup>
130.   <EmbeddedResource Include="appsettings.json" />
131. </ItemGroup>return stream;
132. <ItemGroup>
133.   <EmbeddedResource Include="appsettings.json" />
134. </ItemGroup><ItemGroup>
135.   <EmbeddedResource Include="appsettings.json" />
136. </ItemGroup><ItemGroup>
137.   <EmbeddedResource Include="appsettings.json" />
138. </ItemGroup><ItemGroup>
139.   <EmbeddedResource Include="appsettings.json" />
140. </ItemGroup><ItemGroup>
141.   <EmbeddedResource Include="appsettings.json" />
142. </ItemGroup><ItemGroup>
143.   <EmbeddedResource Include="appsettings.json" />
144. </ItemGroup>}
145. <ItemGroup>
146.   <EmbeddedResource Include="appsettings.json" />
147. </ItemGroup><ItemGroup>
148.   <EmbeddedResource Include="appsettings.json" />
149. </ItemGroup><ItemGroup>
150.   <EmbeddedResource Include="appsettings.json" />
151. </ItemGroup><ItemGroup>
152.   <EmbeddedResource Include="appsettings.json" />
153. </ItemGroup><ItemGroup>
154.   <EmbeddedResource Include="appsettings.json" />
155. </ItemGroup><ItemGroup>
156.   <EmbeddedResource Include="appsettings.json" />
157. </ItemGroup>catch (Exception e)
158. <ItemGroup>
159.   <EmbeddedResource Include="appsettings.json" />
160. </ItemGroup><ItemGroup>
161.   <EmbeddedResource Include="appsettings.json" />
162. </ItemGroup><ItemGroup>
163.   <EmbeddedResource Include="appsettings.json" />
164. </ItemGroup><ItemGroup>
165.   <EmbeddedResource Include="appsettings.json" />
166. </ItemGroup><ItemGroup>
167.   <EmbeddedResource Include="appsettings.json" />
168. </ItemGroup><ItemGroup>
169.   <EmbeddedResource Include="appsettings.json" />
170. </ItemGroup>{
171. <ItemGroup>
172.   <EmbeddedResource Include="appsettings.json" />
173. </ItemGroup><ItemGroup>
174.   <EmbeddedResource Include="appsettings.json" />
175. </ItemGroup><ItemGroup>
176.   <EmbeddedResource Include="appsettings.json" />
177. </ItemGroup><ItemGroup>
178.   <EmbeddedResource Include="appsettings.json" />
179. </ItemGroup><ItemGroup>
180.   <EmbeddedResource Include="appsettings.json" />
181. </ItemGroup><ItemGroup>
182.   <EmbeddedResource Include="appsettings.json" />
183. </ItemGroup><ItemGroup>
184.   <EmbeddedResource Include="appsettings.json" />
185. </ItemGroup><ItemGroup>
186.   <EmbeddedResource Include="appsettings.json" />
187. </ItemGroup>Console.WriteLine("OpenAppPackageFileAsync Exception => " + e.Message);
188. <ItemGroup>
189.   <EmbeddedResource Include="appsettings.json" />
190. </ItemGroup><ItemGroup>
191.   <EmbeddedResource Include="appsettings.json" />
192. </ItemGroup><ItemGroup>
193.   <EmbeddedResource Include="appsettings.json" />
194. </ItemGroup><ItemGroup>
195.   <EmbeddedResource Include="appsettings.json" />
196. </ItemGroup><ItemGroup>
197.   <EmbeddedResource Include="appsettings.json" />
198. </ItemGroup><ItemGroup>
199.   <EmbeddedResource Include="appsettings.json" />
200. </ItemGroup>}
201. <ItemGroup>
202.   <EmbeddedResource Include="appsettings.json" />
203. </ItemGroup><ItemGroup>
204.   <EmbeddedResource Include="appsettings.json" />
205. </ItemGroup><ItemGroup>
206.   <EmbeddedResource Include="appsettings.json" />
207. </ItemGroup><ItemGroup>
208.   <EmbeddedResource Include="appsettings.json" />
209. </ItemGroup><ItemGroup>
210.   <EmbeddedResource Include="appsettings.json" />
211. </ItemGroup><ItemGroup>
212.   <EmbeddedResource Include="appsettings.json" />
213. </ItemGroup>return null;
214. <ItemGroup>
215.   <EmbeddedResource Include="appsettings.json" />
216. </ItemGroup><ItemGroup>
217.   <EmbeddedResource Include="appsettings.json" />
218. </ItemGroup><ItemGroup>
219.   <EmbeddedResource Include="appsettings.json" />
220. </ItemGroup><ItemGroup>
221.   <EmbeddedResource Include="appsettings.json" />
222. </ItemGroup>}

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附加到 builder.Configuration

1. var stream = LoadMauiAsset().Result;
2. builder.Configuration.AddJsonStream(stream);

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附:使用内置资源方式

需要在项目属性中设置生成操作为嵌入资源

1. <ItemGroup>
2.   <EmbeddedResource Include="appsettings.json" />
3. </ItemGroup>

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代码 BlazorMaui 为工程名

1. var a = Assembly.GetExecutingAssembly();
2. using var stream = a.GetManifestResourceStream("BlazorMaui.appsettings.json");
3. builder.Configuration.AddJsonStream(stream);

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项目地址

https://github.com/densen2014/BlazorMaui
https://gitee.com/densen2014/BlazorMaui
关联项目

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