Debugging unmanaged application and managed C# dll at the same time

Question

My setup:
Application.exe (Visual Studio 6.0 C++)
Component.dll (Visual Studio 2010 C#)
Application.exe uses Component.dll

I want to be able to debug my Visual Studio 6.0 C++ application and the Visual Studio 2010 C# component that it uses at the same time but I'm not sure if this is possible or not.

I tried to launch the application from Visual Studio 6.0 and attach to that process ( Application.exe ) in my Visual Studio 2010 component solution but when I go to attach to the process ( Application.exe ) it is greyed out. I tried switching the Attach To: to Native but this does not allow me to attach to this process. My Application.exe is still greyed out in the window.

Is it possible to do this and if so how?

Answer 1

There can be only one debugger attached to a process, that's why the selection is grayed out. You have little use for the VS6 debugger, it doesn't know anything about managed code. You'll have to debug this from VS2010. Right-click your C# project, Properties, Debug. Select "Start external program" and select your C++ .exe. Tick the "Enable unmanaged code debugging option".

Set a breakpoint in your C# code and press F5 to start the .exe. The breakpoint indicator will turn solid as soon as the C++ code loads you DLL. Debugging the C++ code might be possible too although you're working with a .pdb from the previous century. You cannot single-step from the managed code into the C++ code, you have to set a breakpoint.

Answer 2

You cannot attach two different debuggers to the same process.

Instead, you can attach it only to VS2010, but attach it as both managed and native.