How can I use XAML custom control in Windows Runtime Component?

This is a simple program to refer XAML custom control in Windows Runtime Component.

Currently, only C++ stub works, C# stub show something but just a blank.

This repository was made to "Ask Question" in Microsoft Q&A but I'd like to get any help from many persons.

Previously I've made "NetProjection" repository but it became a little complicated. So I re-make this repository to build simpler samples.

Motivation

Get performance with C++ and productivity with C#! Yeah, it's a Microsoft recommended way, but hard way especially for enterprise application.

I intended to make modern desktop application in C# but use DirectX in C++.

But, before going there, I stucked using XAML custom control in WRC. Though there are some related documents here and there, they avoids using XAML control nor make as separated library. I'm keep asking, "Is this possible?" but no answer obtained, yet.

Purpose of the program

The final purpose of this repository is to show XAML control in WRC on C# stub.

Isn't it simple? Then I make two projects. One is library contains a XAML custom control. The other is a stub that refers the library and show/consume the XAML control.

I'd like to go in two steps below.

1. make library in C++/WinRT and make stub also in C++/WinRT.
2. make library in C++/WinRT and make stub in C#.

Now I'm in step 2.
Between step 1 and 2, there might be a .Net 6's restriction, that we must make NuGet package. Using NuGet package is also a hard way for debugging.

I'll use Microsoft's example "BgLabelControl" as XAML control. I would like to make the library as independent solution.

File structure

• Solution: "CppXamlWRC": contains two projects.
  • "CppXamlWRC": An WRC project which include famous XAML custom control "BgLabelControl".
  • "WRC2CsProjection": A projection project of "CppXamlWRC" to C# that makes NuGet package named as "CppXamlWRC.0.1.0-prerelease.nupkg". (The version number may vary.)
• Solution: "StubCpp": contains C++/WinRT stub to use the library.
• Solution: "StubCs": contains C#/WinRT stub to use the library.

The build directory "_build" is made at just under top directory.

Currently no C# items are provided.

Status

• 09/24/2022
  • fix C++(App) - C++(WRC) reference issue and can build/run without errors. "Pch.h" and "App.xaml" were the key.
  • Add WRC projection project from C++ to C#. Add C# stub, "StubCs".
  • If the property "Height" and "Width" specified, there seems a blank. So it could refer something but default form/color/text is not shown correctly.
• 09/22/2022
  Now I'm checking App.xaml of stub project. Modification seems to make some difference but same as before.
• 09/22/2022
  Reference by project(*.winmd). Build fails at C++ stub. The output is;

  1>XamlTypeInfo.g.cpp 
  1>D:\Source\GitHub\XAMLCpp2CsProjection\StubCpp\StubCpp\Generated Files\XamlTypeInfo.g.cpp(179,28): error C2039: 'CppXamlWRC': is not a member of 'winrt'
  

Reproducing Error

• Open CppXamlWRC\CppXamlWRC.sln
• Restore NuGet packages.
• build the solution in x64/release.
• Close the solution.
• Open StubCs\StubCs.sln
• Restore NuGet packages.
• build the solution in in x64/release or x64/debug.

I think these solutions can be unified... Sorry for inconvenience.

Reference

• Build XAML controls with C++/WinRT
• Generate a C# projection from a C++/WinRT component, distribute as a NuGet for .NET apps
• Walkthrough—Create a C#/WinRT component, and consume it from C++/WinRT
• Walkthrough—Create a C# component with WinUI 3 controls, and consume it from a C++/WinRT app that uses the Windows App SDK