Question

So in visual studio i have my solution with two projects, first one is managed c++ code and second one is unmanaged c++ library (waffles). I want to use classes from library in my managed code.

If i simply add ‘include “GMacros.h”‘, then i get ‘cannot compile with /clr’ error. Tried to wrap include in #pragma unmanaged/managed, but it doesnt seem to work.

Is there anything i can do without editing external library code or writing any wrappers?

Answer 1

Unmanaged code can’t be called directly in managed .NET. You need to add __declspec(dllexport) to your functions’ declarations that should be visible outside the unmanaged library:

public:
    void __declspec(dllexport) MyUnmanagedMethod();

And then in your managed code write a simple wrapper like this:

public ref class Wrapper
{
public:
    [DllImport("MyUnmanagedLibrary.dll")]
    static extern void MyUnmanagedMethod();
}

Now you can call Wrapper.MyUnmanagedMethod like any other static method from you managed code.