fabulous-dev/FSharp.Android.Resource: MSBuild task to expose resources to F# .NET Fx / .NET Android projects · GitHub

MSBuild task to expose resources to F# Xamarin.Android / .NET Android projects up until .NET 7.

Starting .NET 8, F# Android projects work out of the box without the need for this library.

Microsoft improved access to assets in your Android apps. They generate an assembly named _Microsoft.Android.Resource.Designer which contains all your Android assets, instead of silently injecting C# code into your F# projects.

1. Replace the old type provider with the new package for your Android project

- <PackageReference Include="Xamarin.Android.FSharp.ResourceProvider" />
+ <PackageReference Include="FSharp.Android.Resource" />

2. Remove the following properties from your Android project fsproj file. They are managed by FSharp.Android.Resource

<PropertyGroup>
-   <AndroidResgenFile>Resources/Resource.designer.cs</AndroidResgenFile>
-   <AndroidUseIntermediateDesignerFile>false</AndroidUseIntermediateDesignerFile>
</PropertyGroup>

3. Run the build one time; it will fail but it's ok. This generates the resource assembly.
4. Reload your project to be able to see the new resource assembly
5. Add do Resource.UpdateIdValues() to your MainActivity (or whichever activity is the first one to display)

type MainActivity() =
    inherit Activity()
    
    // This is required for the app to pick up the right resources
    do Resource.UpdateIdValues()
    
    member _.OnCreate(bundle) =
      base.OnCreate(bundle)
      
      // Now you can use Resource like usual
      this.SetContentView(Resource.Layout.Main)

6. Build one more time. This time it should complete successfully.
7. Everything should be working, enjoy!

Given the first build will always fail, you can use the following steps to workaround it:

1. Execute a build using the target CompileResourceDesignerForFSharp
2. Execute a normal build

msbuild -t:CompileResourceDesignerForFSharp
msbuild -t:Build