This sample demonstrates how to use Registration-free WinRT a new feature in Windows 10 Version 1903 to reference a C++ Windows Runtime component in a non-packaged C# desktop app. It contains a C# console app (CSharpConsole.csproj) and a WinRT Component (WinRTComponent.vcxproj).

You can learn more about Registration-free WinRT here.

The C# desktop app uses:

The Microsoft.VCRTForwarders.140 NuGet package to manage C++ Runtime dependencies for the C++ component. The GitHub repo can be found here.

Requirements

The sample requires Windows 10 Version 1903.

Instructions

C# app

A non-packaged C# console app referencing a C++ WinRT Component

The C# app has a visual Studio reference to the WinRTComponent Project. To add a VS reference to a project right click on the project, then select Add, Reference, Projects, then select the target project to reference.
The specific DLLs and classes (from the WinRT component) being referenced should be declared in the Win32 Application manifest - CSharpConsoleApp.exe.manifest.

To add a new Win32 Application Manifest to a desktop app, right click on the project, then select Add, New Item, General, Application Manifest File, and name it yourappname.exe.manifest.

For the system to locate the component DLLs specified in the application manifest at runtime, the DLLs must be in the same directory as the app's .exe. This project uses a Post Build Event to copy the component DLL to the app's output directory:

copy /Y "$(SolutionDir)WinRTComponent\bin\$(Platform)\$(Configuration)\WinRTComponent.dll"  "$(SolutionDir)$(MSBuildProjectName)\$(OutDir)WinRTComponent.dll"

To add your own Post Build Event to your C# project right click on the project, then select Properties, Build Events, Post Build Event Command line

WinRTComponent

A simple C++ WinRT Component with a class returning a string

The component is written using C++/WinRT instead of C++/CX. Therefore, it requires an installed Nuget Package: Microsoft.Windows.CppWinRT.
To manage the specific C++ Runtime Dependencies of the WinRT component, the app uses the Microsoft.VCRTForwarders.140 NuGet package.

Building and running the sample

Load the Project solution.
Retarget the solution to the SDK version on your machine: Right click, Retarget solution
Build the WinRTComponent project.
Build the CSharpConsoleApp project
Run the app