Hi everybody,

I have some troubles with using my managed C#.Net code in unmanaged C++
code through COM.

I have troubles with passing C# objects to C++ code.
- I have an interface IObjectPass and an object ObjectPass that
implements the interface.
- I have an interface IPassedObject and an object PassedObject that
implements the interface
- I want to assign the object PassedObject via the ObjectPass's
function 'getIPassedObject' parameter.
The code is displayed below.

When I now call the ObjectPass object in C++ through COM and get the
PassedObject, something is not realy going ok. Could somebody give me
some more insight on what happens here. The C++ code is as well
displayed.

Thanks in advance.

Kind regards,

Gerben Heinen

### C# ###
using System;
using System.Runtime.InteropServices;

namespace ClassLibrary1
{
    [Guid("71162EC2-6933-43a2-ADB9-03D5B3C53245")]
    public interface IObjectPass
    {
       void getIPassedObject(ref IPassedObject Ipassedobject);
    }

    [Guid("1767F869-134A-41c0-89EA-5800F7B66B8C")]
    public class ObjectPass : IObjectPass
    {
        public ObjectPass()
        {
            //
            // TODO: Add constructor logic here
            //
        }

        private PassedObject passedobject = new PassedObject();

        public void getIPassedObject(ref IPassedObject Ipassedobject)
        {
           Ipassedobject = passedobject;
        }
    }

    [Guid("A2E71471-6329-4aa2-8F58-469C5F8AD9AD")]
    public interface IPassedObject
    {
        string PassedString
        {
            get;
            set;
        }
    }

    [Guid("2C35ABF6-67A2-4553-BCEC-508117649B34")]
    public class PassedObject : IPassedObject
    {
        public PassedObject()
        {
        }

        private string passedstring = "Ok!";

        public string PassedString
        {
            get { return passedstring; }
            set { passedstring = value; }
        }
    }

}

##########

### C++ ###

// Win32CommCaller.cpp : Defines the entry point for the console
application.
//

#include "stdafx.h"
#include <windows.h>
#include <stdio.h>

#import <mscorlib.tlb> raw_interfaces_only
#import "ClassLibrary1.tlb" no_namespace named_guids

int _tmain(int argc, _TCHAR* argv[])
{
    IObjectPass *op = NULL;
    IPassedObject *po = NULL;
    char *val = NULL;
    _bstr_t *bstrt = NULL;
    BSTR *bstr = NULL;

    CoInitialize(NULL);

    HRESULT hr = CoCreateInstance(CLSID_ObjectPass,
        NULL, CLSCTX_INPROC_SERVER,
        IID_IObjectPass, reinterpret_cast<void**>(&op));

    op->getIPassedObject(&po);

    po->get_PassedString(bstr);

    printf("Value: %s",bstr);

   
    CoUninitialize();
   
    return 0;
}

###########