Hello,

 I have a C# application which creates two C++ COMs, and then pass
one to another. the code snippet as follows:

COM1 and COM2 are two COMs implemented in ATL.

in C#:
COM1.CCOM1Class com1 = new COM1.CCOM1Class ();
COM2.CCOM2Class com2 = new COM2.CCOM2Class ();
... ...
(1) com1.SetCOM2(com2);
......

The prototype of SetCOM2 in COM1.CCOM1Class com1 is:
   
[id(1), helpstring("method SetCOM2 ")] HRESULT SetCOM2 ([in]
IDispatch* pICOM2);

in its definition:
STDMETHODIMP CCOM1Class ::SetCOM2 (IDispatch* pICOM2)
{
    HRESULT hr = S_OK;
    try
    {
        COM2::ICOM2Ptr ptr;
(2)        hr = pICOM2->QueryInterface(COM2::IID_ICOM2, (void**)&ptr);

        if(ptr == NULL)    //Test only
        {
        }
    }
    catch(...)
    {
        ATLASSERT(FALSE);
    }

    return hr;
}

The code was compiled, but when was executed, at point (2), return hr
indicated the Empty pointer. I think the point (1) may be not correct,
but I don't know how to fix it.
 Please help or point to related docs.

 Thanks in advance.

Steven Wang