CompiledBindings.WPF package reference breaks CsWin32

[chucker]

(I'm unsure whether to file this here, or over at https://github.com/microsoft/CsWin32/)

Something about the build process is incompatible with the CsWin32 project (and perhaps other source generators as well?).

To reproduce,

1. create an empty .NET 9 WPF app.
2. modify WpfApp1.csproj as follows:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>WinExe</OutputType>
    <TargetFramework>net9.0-windows</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
    <UseWPF>true</UseWPF>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.Windows.CsWin32" Version="0.3.106">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
  </ItemGroup>

</Project>

I.e., add that one package reference.

3. modify MainWindow.xaml.cs as follows:

using System.Windows;
using System.Windows.Interop;

namespace WpfApp1
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        public void SetAsForegroundWindow()
        {
            // handle focus https://stackoverflow.com/a/75705911
            if (PresentationSource.FromVisual(this) is HwndSource hwndSource)
                _ = Windows.Win32.PInvoke.SetForegroundWindow((Windows.Win32.Foundation.HWND)hwndSource.Handle);
        }
    }
}

I.e., add that one method. It's just a dummy method that calls code generated by the Microsoft.Windows.CsWin32 dependency.

4. add a file NativeMethods.txt:

SetForegroundWindow

5. do a clean build. This will work.
6. now, modify WpfApp1.csproj again:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>WinExe</OutputType>
    <TargetFramework>net9.0-windows</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
    <UseWPF>true</UseWPF>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="CompiledBindings.WPF" Version="1.0.18"/>
    <PackageReference Include="Microsoft.Windows.CsWin32" Version="0.3.106">
      <PrivateAssets>all</PrivateAssets>
      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
    </PackageReference>
  </ItemGroup>

</Project>

I.e., add this project as a package reference.

7. do another clean build. Suddenly, we get build errors:

1>C:\Users\chucker\source\repos\temp\WpfApp1\NativeMethods.txt(1,1,1,20): warning PInvoke001: Method, type or constant "SetForegroundWindow" not found
1>C:\Users\chucker\source\repos\temp\WpfApp1\MainWindow.xaml.cs(20,21,20,28): error CS0103: The name 'Windows' does not exist in the current context
1>C:\Users\chucker\source\repos\temp\WpfApp1\MainWindow.xaml.cs(20,64,20,71): error CS0246: The type or namespace name 'Windows' could not be found (are you missing a using directive or an assembly reference?)
1>Done building project "WpfApp1.csproj" -- FAILED.

Is there something special I can do to make this combination work?

[levitali]

I work on the solution to this problem