如何在 Visual Studio 2019 中调试 .NET 5 WinForms 应用程序，该应用程序引用 .NET Framework 4.8 class 库

Question

I have test .NET 5 WinForms application that references .NET Framework 4.8 class library - Github link .

I suppose it's possible because of .NET Framework compatibility mode

When I'm trying to debug a class library in Visual Studio 2019 16.8.4 (by starting my .NET 5 application) I get an error:

The debugger was configured to use the Desktop CLR (.NET Framework) Managed debugger, but the target process loaded the CoreCLR (.NET Core) runtime. The debugger was configured to use the Desktop CLR (.NETFramework) Managed debugger, but the target process loaded the CoreCLR (.Net Core) runtime. To debug this project, configure it to use the 'Managed (CoreCLR)' debugger.

Where can I find an option to use the 'Managed (CoreCLR)' debugger .

Thank you in advance.

UPDATE If I start debugging from .NET 5 application project - I can step into .NET Framework 4.8 class library. But I want to debug from class library project.

Answer 1

One useful function is to change your net framework project from non-sdk into new-sdk csproj format.

1) create a net core class library project and then enter its csproj file and then change the targetframework into:

<TargetFramework>net48</TargetFramework>

So you got a net framework4.8 project which is compatible with CoreCLR .

See this document .

When you finish it, please move your non-sdk net framework4.8 files into the new one.

2) use Attach to Process and it should has a execute program to run the code of the lib project.

You can check this issue to get the detailed steps, when you open Attach to Process and remember to choose Managed(.Net Core,NET5+) and that is the debugger.

This is a similar issue about it .

In fact , I recommend the solution one and solution two might have some small problems.