hi,

 I want to pass a function pointer to COM, so that COM can callback in some
situation.

/////////////////////////////////////
// C# compile into COM
using System;
using System.Runtime.InteropServices;
namespace Whatever
{
public delegate void dProc();
[ClassInterface(ClassInterfaceType.AutoDual)]
[Guid("6DAFA2C2-BE89-4af3-92CF-A278E81D9C2D")]
public class MyClass
{
 public bool SetHandler([MarshalAs(UnmanagedType.FunctionPtr)]dProc dlgt)
 {
  System.Console.WriteLine("in the COM\n");
  return true;
 }
}
}

////////////////////////////////////////
// C++ use the COM
#define _WIN32_WINNT 0x0501
#include <objbase.h>
#include <iostream>
#import "d:\project\lev3test\mscorlib.tlb" raw_interfaces_only
#import "d:\project\lev3test\ericbase.tlb" no_namespace named_guids
extern "C"
void __stdcall ProcData()
{
return;
}
int main ()
{
::CoInitialize(NULL);

try
{
 _MyClassPtr pPtr(__uuidof(MyClass));
 int dlgt = reinterpret_cast<int>(ProcData);
 pPtr->SetHandler(dlgt);
}
catch(_com_error e)
{
 std::cout << e.ErrorMessage() << std::endl;
}
::CoUninitialize();
getchar();

return 0;
}
// source end
/////////////////

 two projects compile and link well. but when i run the program, i got an
exception at "pPtr->SetHandler(dlgt)" saying "invalid agument".

 What's wrong here?

 Thanks in advance.

Regards,
Eric