Re: Newbee Question: How to return an void* in a VARIANT parameter?

From:

"Alexander Nickolov" <agnickolov@mvps.org>

Newsgroups:

microsoft.public.vc.atl

Date:

Fri, 20 Apr 2007 12:01:44 -0700

Message-ID:

<#eZgX53gHHA.4936@TK2MSFTNGP04.phx.gbl>

Not in this context, but it wouldn't work if you had a plain
object pointer (here you have CComObject<> pointer) and
the object implements multuiple interfaces. GetUnknown()
gives you the COM identity of the object.

--
=====================================
Alexander Nickolov
Microsoft MVP [VC], MCSD
email: agnickolov@mvps.org
MVP VC FAQ: http://vcfaq.mvps.org
=====================================

"Jason S" <jmsachs@gmail.com> wrote in message
news:1177073229.047541.145000@d57g2000hsg.googlegroups.com...

On Apr 19, 2:41 pm, "Alexander Nickolov" <agnicko...@mvps.org> wrote:

STDMETHODIMP class::GetHandle(whatever, IDispatch** ppDisp) {
   void* handle = ::GetHandle(whatever);

   CComObject<CHandler> *pObj = NULL;
   HRESULT hr = CComObject<CHandler>::CreateInstance(&pObj);
   if (FAILED(hr)) {
       return E_MEMORY;
   }
   pObj->init(handle);
   return pObj->GetUnknown()->QueryInterface(ppDisp);

}

just curious, why the call to GetUnknown() ? is it an error to do pObj-

QueryInterface(ppDisp) instead?