Debugging A VC++ 6 DLL Called From C#

I have an old DLL written in Visual Studio 6 which I am calling from C# written in Visual 开发者_运维百科Studio 2010. The DLL is not working properly and I want to debug into it. How can I do this? I have the source code project but cannot see how I can step into it.

Note: When I say "doesn't work", the call to the DLL succeeds and it gets a little way through the code in the DLL before failing, but I want to track down exactly where.

The technique of debugging a DLL is described here on MSDN. You'll need to do this from Visual Studio 6 (i.e. the tool that developed the DLL) and so the terminology will have changed. But the principles remain the same.

Attaching VS6 debugger on the .NET process shall work, as long you have the PDB file with the corresponding binary and the sources. You can break only on DLL code, however.

Attaching another VS+ shall work if the flag "Allow unmanaged debugging" is checked, but there is a possibility that symbols are not loaded by the debugger. A recompilation of the DLL shall solve the last problem.

Open Visual C++ Dll project, set breakpoint where you need. In the Project properties, Debug, Executable for debug session, type .NET executable file which uses this Dll. Start debugging (Go). When VC++ function is called, debugger breaks. Using this way, you can debug only unmanaged VC++ code.

Another way is to start debugging from .NET client in mixed debugging mode. Add VC++ project to the solution and rebuild it to debug both managed and unmanaged code.