.net8 Android not building because Resources from resx not found. #9057

dellis1972 · 2024-06-26T08:38:34Z

With the release of the new Resource Designer assembly we purposely removed the existing legacy Resource.designer.cs file from the @(Compile) ItemGroup. This is so that we did not get any clashes with the new system.

Unfortunately the name Resource.designer.cs is also used by developers as the name for the generated class when using .resx files. As a result we got the above bug report because the class was disappearing.

error CS0234: The type or namespace name 'Resources' does not exist in the namespace 'StringResourcesBug' (are you missing an assembly reference?)

It turns out that the _RemoveLegacyDesigner was being a bit too aggressive with its removal of files. Because it was matching on filename only it was removing files which had nothing to do with Android Resources. This would cause the above error.

The fix in this case is to check for additional metadata. In the case of .resx file designers they typically have a DependentUpon metadata to signal that they are generated from the .resx. So we should check this metadata to make sure it is NOT set before removing a file.

A new unit test was added to test this fix and it worked. But it did show up one other issue. In certain cases we would end up with two Resource classes in the same namespace. This would then cause the following build error.

error CS0260: Missing partial modifier on declaration of type 'Resource'; another partial declaration of this type exists

This is because the two classes had different modifiers. We could also get an error if the access modifiers are different (public vs internal). So lets add a new MSBuild property AndroidResourceDesignerClassModifier. This property defaults to public, but can be overridden by the user to control the access modifier of the generated class.

Also we have to remove the GeneratedCode Attribute usage on the generated Resource class. Since it can conflict with the one that is auto added to the Resource.designer.cs generated by the resx code generator. If we leave this in place we get the following error.

__Microsoft.Android.Resource.Designer.cs(15,3,15,16): error CS0579: Duplicate 'GeneratedCode' attribute

Unfortunately the GeneratedCode Attribute [1] is marked as AllowMultiple=false and in this case there is no way to know if it exists on the class already as its a partial class.

[1] https://learn.microsoft.com/en-us/dotnet/api/system.codedom.compiler.generatedcodeattribute?view=net-8.0

...amarin.Android.Build.Tasks/MSBuild/Xamarin/Android/Xamarin.Android.Resource.Designer.targets

Documentation/docs-mobile/messages/xa1038.md

src/Xamarin.Android.Build.Tasks/Properties/Resources.resx

Documentation/docs-mobile/building-apps/build-properties.md

...amarin.Android.Build.Tasks/MSBuild/Xamarin/Android/Xamarin.Android.Resource.Designer.targets

jonathanpeppers

Otherwise, LGTM.

Documentation/docs-mobile/building-apps/build-properties.md

jonathanpeppers

Overall, LGTM. 👍 I reran some test lanes to check if they will be green.

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/Utilities/InlineData.cs

...amarin.Android.Build.Tasks/MSBuild/Xamarin/Android/Xamarin.Android.Resource.Designer.targets

src/Xamarin.Android.Build.Tasks/Tasks/GenerateResourceDesignerIntermediateClass.cs

Fixes https://github.com/dotnet/maui/issues/19117 With the release of the new Resource Designer assembly we purposely removed the existing legacy `Resource.designer.cs` file from the `@(Compile)` ItemGroup. This is so that we did not get any clashes with the new system. Unfortunately the name `Resource.designer.cs` is also used by developers as the name for the generated class when using `.resx` files. As a result we got the above bug report because the class was disappearing. ``` error CS0234: The type or namespace name 'Resources' does not exist in the namespace 'StringResourcesBug' (are you missing an assembly reference?) ``` It turns out that the `_RemoveLegacyDesigner` was being a bit too aggressive with its removal of files. Because it was matching on filename only it was removing files which had nothing to do with Android Resources. This would cause the above error. The fix in this case is to check for additional metadata. In the case of `.resx` file designers they typically have a `DependentUpon` metadata to signal that they are generated from the `.resx`. So we should check this metadata to make sure it is NOT set before removing a file. A new unit test was added to test this fix and it worked. But it did show up one other issue. In certain cases we would end up with two `Resource` classes in the same namespace. This would then cause the following build error. ``` error CS0260: Missing partial modifier on declaration of type 'Resource'; another partial declaration of this type exists ``` This is because the two classes had different modifiers. We could also get an error if the access modifiers are different (public vs internal). So lets add a new MSBuild property `AndroidResourceDesignerClassModifier`. This property defaults to `public`, but can be overridden by the user to control the access modifier of the generated class.

It causes ``` __Microsoft.Android.Resource.Designer.cs(15,3,15,16): error CS0579: Duplicate 'GeneratedCode' attribute ```

jonathanpeppers reviewed Jun 26, 2024

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...amarin.Android.Build.Tasks/MSBuild/Xamarin/Android/Xamarin.Android.Resource.Designer.targets Show resolved Hide resolved

dellis1972 force-pushed the Issue_maui_19117 branch 2 times, most recently from 690f387 to aad2d2c Compare July 2, 2024 15:27

dellis1972 marked this pull request as ready for review July 2, 2024 15:28

dellis1972 requested a review from jonpryor as a code owner July 2, 2024 15:28