How to attach debugger to step into native (C++) code from a managed (C#) wrapper?

Question

I have a wrapper around a C++ function call which I call from C# code. How do I attach a debugger in Visual Studio to step into the native C++ code?

This is the wrapper that I have which calls GetData() defined in a C++ file:

    [DllImport("Unmanaged.dll", CallingConvention=CallingConvention.Cdecl, 
               EntryPoint = "GetData", BestFitMapping = false)]
        public static extern String GetData(String url);

The code is crashing and I want to investigate the root cause.

Thanks, Nikhil

Answer 1

Check the Debug tab on your project's properties page. There should be an "Enable unmanaged code debugging" checkbox. This worked for me when we developed a new .NET UI for our old c++ DLLs.

If your unmanaged DLL is being built from another project (for a while ours were being built using VS6) just make sure you have the DLL's pdb file handy for the debugging.

The other approach is to use the C# exe as the target exe to run from the DLL project, you can then debug your DLL normally.