CoreIsland

A .NET library that enables building AOT-compiled Win32 desktop apps with WinUI 2 via XAML Islands — no UWP packaging or MSIX required.

It replaces UWP's Application.Start() / runtime marshalling with a custom Application, a Win32 Window hosting DesktopWindowXamlSource, source-generated COM interop, and build-time MSBuild extensions — all compatible with .NET Native AOT.

# Build PublishAot
msbuild .\App1\App1\App1.csproj /t:Publish /p:PublishProfile=win-x64 /p:Platform=x64 /p:Configuration=Release

Features (what CoreIsland has done)

1. Smooth resize synchronization with the XAML framework
2. Build-time XBF→PRI embedding so XAML resources are not loose files
3. Optional Microsoft.UI.Xaml (WinUI 2) support via NuGet
4. Restore certain Windows 10 behaviors to match Windows 11

TODO

• reduce "Microsoft.UI.Xaml.pri" size
• ExtendsContentIntoTitleBar
• release nuget package
• fix when PublishAot on msix packaged (JIT pacakged is fine)
• Verify x:Uid x-generate working correctly

Looking for a C++ version?

Also check Blinue/Xaml-Islands-Cpp; this project is inspired by it.