Re: how to add an event handler for a dynamically created ActiveX

=?Utf-8?B?dGl0YW5pY28=?= <>
Thu, 11 May 2006 07:07:02 -0700
sry, forget my exception description.
figured out, the second parameter pUnk __vfptr isn??t initialized correctly.

ATLINLINE ATLAPI AtlAdvise(IUnknown* pUnkCP, IUnknown* pUnk,
                                           const IID& iid, LPDWORD pdw)
   if(pUnkCP == NULL)
      return E_INVALIDARG;

   CComPtr<IConnectionPointContainer> pCPC;
   CComPtr<IConnectionPoint> pCP;
   HRESULT hRes = pUnkCP->QueryInterface(__uuidof(IConnectionPointContainer),
   if (SUCCEEDED(hRes))
      hRes = pCPC->FindConnectionPoint(iid, &pCP);
   if (SUCCEEDED(hRes))
      hRes = pCP->Advise(pUnk, pdw); // exception here because of pUnk
   return hRes;

don??t know why, because the pUnk parameter is delivered with (IUnknown*)this
from _IDispEvent:

HRESULT DispEventAdvise(IUnknown* pUnk, const IID* piid)
   ATLENSURE(m_dwEventCookie == 0xFEFEFEFE);
   return AtlAdvise(pUnk, (IUnknown*)this, *piid, &m_dwEventCookie);

thx again^^
"titanico" wrote:

thx for this advice, i tried this too already.

// Sink Class
class ATL_NO_VTABLE CSinkEvent :
                public IDispEventImpl<1, CSinkEvent,
                                                 &LIBID_Controls, 1, 0>

           SINK_ENTRY_EX(1, DIID__IExSliderCtrlEvents, 1, PositionChanged)

   HRESULT __stdcall PositionChanged(long nPosition) {return S_OK;}

// Main Class
m_wndSlider = new CAxWindow();
m_wndSlider->Create(..create slider here..);
CComQIPtr<IExSliderCtrl> pSlider;
m_wndSlider->QueryControl(IID_IExSliderCtrl, (void**)&pSlider);
m_pSinkEvent = new CSinkEvent();
m_pSinkEvent->DispEventAdvise((IUnknown*)pSlider); // exception here

First, what is the major and minor version of the type library? I couldn't
find any useful information concerning these parameters.

Because of the exception:
The DispEventAdvise calls IDispEventSimpleImpl::DispEventAdvise then
_IDispEvent::DispEventAdvise then AtlAdvice. Finally here is the Problem:
He does not step into "QueryInterface" and the pUnkCP gets NULL after this
Line and throws exception.

ATLINLINE ATLAPI AtlAdvise(IUnknown* pUnkCP, IUnknown* pUnk,
                                           const IID& iid, LPDWORD pdw)
   if(pUnkCP == NULL)
      return E_INVALIDARG;

   CComPtr<IConnectionPointContainer> pCPC; // does not step into here!!!
   CComPtr<IConnectionPoint> pCP; // does not step into here!!!
           // and does not step into here!!!
   HRESULT hRes =
            // pUnkCP = NULL after the above Line!
   if (SUCCEEDED(hRes))
      hRes = pCPC->FindConnectionPoint(iid, &pCP); // exception here
   if (SUCCEEDED(hRes))
      hRes = pCP->Advise(pUnk, pdw);
   return hRes;

Sry for be annoying, but this stuff drives me crazy.
thx titanico.

"Igor Tandetnik" wrote:

"titanico" <> wrote in message

for completeness the sink class implementation:

class ATL_NO_VTABLE CSinkEvent :
  public IDispEventImpl<1, CSinkEvent>

You need to specify more parameters to IDispEventImpl - the DIID, the
LIBID and the major and minor version numbers of the type library.
With best wishes,
    Igor Tandetnik

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