C++ client for C# dll - function call problem

[boychan2002]

I want to call a function defined in c# dll from a vc++ (6.0) client. The c# dll (Class Library) has a Class which is as followsbr]
using System;
using System.Runtime.InteropServices;

namespace ClassLibrary3
{

public class Class1{
public Class1(){
}
public void fn1(){
System.Windows.Forms.MessageBox.Show("abc");
}
}
}

All the function does is show a message box. In the Build properties I set the 'Register for COM interop' as 'True'. And then I created the dll (along with the type library).

My VC++ client code looks like this (only the relevant code)br]
<stdafx.h>

#import "ClassLibrary3.tlb"
using namespace ClassLibrary3;

<client.cpp>
int main(int argc, char* argv[])
{
HRESULT hresult;
CLSID clsid;
CoInitialize(NULL);
hresult=CLSIDFromProgID(OLESTR("ClassLibrary3.Class1"),&clsid);
_Class1 *t;
hresult=CoCreateInstance(clsid,NULL,CLSCTX_INPROC_SERVER,__uuidof(_Class1),(LPVOID *)t);
t->fn1();
t->Release ();
CoUninitialize();

return 0;
}

When I compile the VC++ client, it gives the error "error C2039: 'fn1' : is not a member of '_Class1' ". After the compilation, ClassLibrary3.tlh is generated( but ClassLibrary3.tli is not generated). That is the reason the functions in the dll classes are not visible.

My question is: Why is the .tli file not being generated? How do I make the Class functions visible to the VC++ client? Eventually I want to open a form in C# dll which has some buttons which perform screen capturing functionality.

thanks in advance

[Leonardo]

I havent worked with C#, but I guess its the same as using an ActiveX DLL from any other app... like Vb or even a Windows COM compoenent like ADO....

This is what I would try

_Class1 t;
t.CreateInstance(__uuidof(Class1));
t->fn1();