Migrating Net free C++ code written in VS 2005 to Visual C++ in VS2010

Question

Our VB6 program currently calls code in a C++ dll. This dll does not need to be registered, it only needs a .def file specifiying the properties and methods. Vb6 late binds to it. The dll is written in VS2005 without a dependency on the Net framework.

As we are migrating our application to Net4 and also want to enhance the C++ dll with new functionality, I was wondering how to migrate the existing C++ code to VC++. I suppose thereafter the dll will just happily integrate in our solution which already contains C# and VB.Net libraries too.

Is there some tutorial/documentation about the do's and don'ts of this plan?

EDIT: I think I have some basic misunderstanding about VC++, thinking that it can be ported to 100% managed code while keeping the C++ syntax. The replies I get seem to indicatie that VC++ will always produce native, unmanaged code?

Answer 1

If you open the VS2005 project file in VS2010, VS2010 will automatically convert the old project to the new project format and the auto-conversion will do it's very best job to get everything correct. This usually works, but not always. So the moral of the story here is, double-check all of the new project's compiler/link settings, to be on the safe side.

Also with VS2010, you have some better interop possibilities between managed and native code: P/Invoke and C++/CLI. P/Invoke is simpler, but you will find that stuff may compile but fail at runtime. C++/CLI is way more flexible, a bit more work, but makes it much easier to debug the interop, when it becomes necessary.

Answer 2

From a pure C++ point of view, you should be able to convert the VS2005 solution and project to VS2010 automatically. If I recall when you load the solution or project into VS2010 it will automatically convert it for you.