equivalent of a c# class in c /CLI when used as a parameter(managed) for a function in c /CLI

Question

I have a c# file as below:

//MyHandler.cs
public **class MyHandler**
{
**Function1(IntPtr handle)**
{....}
Function2(MyImageHandler myImgHandler,int height,int width)
{....}
};

public **class MyImageHandler**
{
FunctionX(string imagePath,int height,int width)
{.....}
};

I am wrapping it using a c++/CLI wrapper dll which contains a header file as follows :

//IWrapper
#pragma once
#include<windows.h>
#include <string>

#ifdef MANAGEDWRAPPER_EXPORTS
#define DLLAPI  __declspec(dllexport)
#else
#define DLLAPI  __declspec(dllimport)
#pragma comment(lib,"D:\\MY\\MYY1\\Wrapper\\Debug\\MyFinalLibrary.lib")
#endif

class IWrapper
{
public:
   virtual DLLAPI void Function1(HWND  handle)=0;
   **virtual __stdcall void Function2(MyImageHandler myImageHandler,int width,int height)=0;**
};

** MyImageHandler is a managed class.so i am exporting it through __stdcall.Am i right in doing this? ** Now i have a header file implementing the above header file and then a cpp file as follows::

#include "Wrapper.h"
#include "IWrapper.h"
#include<vcclr.h>
#include <windows.h>
Function1(HWND handle)
{....}
Function2(MyImageHandler myImgHandler,int height,int weight)
{
//Here I need to typecast the MyImageHandler type to a managed handle
}

Answer 1

I just tested this on Visual Studio 2005, which worked:

//Project: InteropTestCsLib, class1.cs
namespace InteropTestCsLib
{
    public class Class1
    {
        public int Add(int a, int b) { return a+b; }
    }
}

A C++/CLI project with an assembly reference to the C# one, and the project link option "Ignore import library" disabled (it was enabled by default)

//Project: InteropTestCppCliLib, InteropTestCppCliLib.h
namespace InteropTestCppCliLib {

    public ref class MyWrapper abstract sealed
    {
    public:
        static int Add(int a, int b);
    };
}

//Project: InteropTestCppCliLib, InteropTestCppCliLib.cpp
namespace InteropTestCppCliLib {

int MyWrapper::Add(int a, int b)
{
    InteropTestCsLib::Class1^ obj = gcnew InteropTestCsLib::Class1();
    return obj->Add(a, b);
}

}

//Free function, neither in a namespace nor class, but still managed code
extern "C" int __stdcall MyWrapperAdd(int a, int b)
{
    return InteropTestCppCliLib::MyWrapper::Add(a, b);
}

And the module-definition file (.def):

LIBRARY "InteropTestCppCliLib"
EXPORTS
    MyWrapperAdd

And finally an empty native Win32 C/C++ project, with a project dependency on the C++/CLI DLL (or simply, a project that imports the import library it generated):

/*Project: InteropTestUnmanagedApp, main.c*/
#include <stdio.h>

__declspec(dllimport) int __stdcall MyWrapperAdd(int a, int b);

int main(void)
{
    int x = 10;
    int y = 32;
    int result = MyWrapperAdd(x, y);
    printf("%d + %d = %d\n", x, y, result);
    return 0;
}

The C project called the C++/CLI one seamlessly.