How to use CsWinRT in a Visual Basic Project project

[operatortwo]

Based on this C# console sample, I would like to create a console, a WinForms, and a WPF sample in Visual Basic.
Console build was successful, but I get errors when building the WinForms and WPF projects.
\Generated Files\CsWinRT\WinRTEventHelpers.cs

// some comments
using System;
namespace WinRT
{

}

Build tells me that there are Visual-Basic-Syntax-Errors in the .cs file. (BC30035)

My current workaround is to add a C# console project to the solution, install the required packages 'CsWinRT' and 'midi2' there, and build the C# project.
In the Visual Basic project, I can now add a reference to the generated Midi2.NetProjection.

The corresponding code can be found here

Is my workaround the right way, or can it be done better?

[Dongle (dongle-the-gadget)]

You can't use CsWinRT directly in Visual Basic because it generates C# code. What you need to do is to create a C# project, add CsWinRT in there and add a project reference to the Visual Basic project.

[Manodasan Wignarajah (manodasanW)]

Based on your error and looking at your project, I feel like you are just trying to consume a generated cswinrt projection and not trying to generate one yourself, right? If so, you can try removing the cswinrt package reference from your project and it should still build as the cswinrt dependencies should come from the target framework.

[operatortwo]

My main focus is on adapting a C# example on the topic of Midi2 to Visual Basic. So, first I tried to stay as close to the original as possible. The source's KB contains additional information:

Consuming from C# Desktop App
...
The package contains the .NET (C#) projection for .NET 7 and .NET 8. You will still need to install the C#/WinRT NuGet package in your project because we use other Windows SDK types from Windows.Foundation and more.

Note that other .NET languages (like Visual Basic) may work, but have not been tested.
...

At the moment I don't fully understand the functions of CsWinRT. However, I am able to create the desired project in Visual Basic, thanks to C# and CsWinRT.

[Manodasan Wignarajah (manodasanW)]

You are still using CsWinRT generated projections without referencing the CsWinRT NuGet package. Typically, you reference the CsWinRT NuGet package for the tooling to generate a projection for a WinMD, for WinRT component authoring support, or to pick up a newer version of the WinRT.Runtime.

Otherwise as a consumer of a projection, you typically just need to reference the projection, and things should work without directly referencing the CsWinRT NuGet package itself. I haven't tried building your sample yet, but it looked like you were just consuming a generated projection and not generating one.

because we use other Windows SDK types from Windows.Foundation and more

We basically generate the Windows SDK projection package using CsWinRT and distribute it as a targeting pack. In the target framework, when you have something like net8.0-windows10.0.26100.0, we will bring that down along with a version of WinRT.Runtime. That is where you typically get the foundation and other Windows SDK types from.

[operatortwo]

Thank you for the explanation.
Yes, I only want to consume the projection.
When I try to use this source package stand alone, I get an NETSDK1130 error because of a reference to a .winmd file.
This could be an issue in the source package.

[Manodasan Wignarajah (manodasanW)]

It looks like the WinMD along with the projection DLL is in the ref folder of the nuget rather than just the projection DLL which is why this error is seen. This might be why they were referencing the CsWinRT package before because the CsWinRT NuGet package has logic to filter out any WinMD references. Can you try adding the below property while still referencing the CsWinRT package. It would allow for the WinMD filtering logic to happen while not trying to generate a projection.

<CsWinRTEnabled>false</CsWinRTEnabled>

[operatortwo]

Great, that works perfectly!

I made a test with the source package:

For .net8.0

When I remove

<ItemGroup>
            <Reference Include="$(NugetRoot)ref\native\Microsoft.Windows.Devices.Midi2*.winmd" />
</ItemGroup>

in .targets
and delete the *.winmd from /ref

then I can use the Source Package Stand-alone.

[Pete Brown (Psychlist1972)]

Thanks all for helping with this. I am the owner of the Microsoft.Windows.Devices.Midi2 NuGet package, and will look to apply some or all of the recommendations here. The NuGet package itself is consumed by .NET languages, but also C++ via NuGet and C++ via a vcpkg which wraps the NuGet download.