OCX containment

Ed Kaltenbach -- kaltenba@ataway.aptec.com
Wednesday, February 14, 1996


Hello All,

I am using MSVC++ 4.0 on Windows 95

My view is derived from CView.  I allow the user to add
OLE Controls to the view by clicking where he/she wants
the new OCX to be created.

To test I create an OCX with MSVC++ 4.0 called TestocxCtrl.
It is just the basic ellipse control that gets created by
VC++.  I did not add any code of my own to it yet.

I am having some odd problems when I exit my program.

Here is how I add the control to the view:

void CContView::OnLButtonDblClk(UINT nFlags, CPoint point)
{  
  
  HRESULT hr = AfxGetClassIDFromString("TESTOCX.TestocxCtrl.1", &clsid);

  // some error checking is done here

  m_windows[m_numControls]->CreateControl(clsid, "Channel", WS_VISIBLE,
                                tempRect, this, WM_USER + m_numControls,
                                NULL,FALSE,NULL);

  LPUNKNOWN temp = m_windows[m_numControls]->GetControlUnknown();

  HRESULT res = temp->QueryInterface(IID_IOleObject,
                                     (void**)&m_OleControls[m_numControls]);
  .
  .
  .

Now I want to call DoVerb to hide the control and I will call OleDraw in OnDraw
for the view.  This way I can get mouse clicks in the rect containing the OCX.

  m_OleControls[m_numControls]->DoVerb(OLEIVERB_HIDE,0,???,0,m_hWnd,&tempRect);

What should I pass as the 3rd parameter to DoVerb?  I tried passing the view
"(IOleClientSite*)this", and everything seems to work fine, but when I exit the
program I get an ASSERT in wincore.cpp line 360.  The line is:
  ASSERT( pWnd != NULL);

I then tried to call GetClientSite for the IOleObject:
  m_OleControls[m_numControls]->GetClientSite(&temp_clientSite); 

When I passed temp_clientSite as the 3rd parameter to DoVerb everything seems
fine until I exit the program.  On exiting I get an ASSERT in cmdtarg.cpp 
at line 52.  The line is:
  ASSERT( m_dwRef <= 1);  
The value of m_dwRef is 2.

If I never call DoVerb with OLEIVERB_HIDE, then I don't have any problems.
I can call DoVerb with OLEIVERB_SHOW and OLEIVERB_PROPERTIES and everything is
fine.  I pass "(IOleClientSite*)this" as the 3rd parameter for the SHOW and
PROPERTIES verbs.

Can someone please help me?  I don't know where else to turn.

Thanks,
Ed Kaltenbach

---------------------------------------------------------------
Ed Kaltenbach                  Email: kaltenba@ataway.aptec.com
---------------------------------------------------------------

---

John & Annette Elsbree -- elsbree@msn.com
Friday, February 16, 1996

From: 	owner-mfc-l@netcom.com on behalf of Ed Kaltenbach

> Now I want to call DoVerb to hide the control and I will call OleDraw in 
OnDraw
> for the view.  This way I can get mouse clicks in the rect containing the 
OCX.
>  m_OleControls[m_numControls]-
>  >DoVerb(OLEIVERB_HIDE,0,???,0,m_hWnd,&tempRect);

Why use DoVerb, when you can just call ShowWindow? E.g., 

	m_windows[m_numControls]->ShowWindow(SW_HIDE);

This *does* do the right thing (i.e., it calls DoVerb).

> What should I pass as the 3rd parameter to DoVerb?  I tried passing the view
> "(IOleClientSite*)this", and everything seems to work fine, but when I exit 
the
> program I get an ASSERT in wincore.cpp line 360.  The line is:
>   ASSERT( pWnd != NULL);

'this' (which I assume is the view window that contains the controls) isn't 
derived from IOleClientSite, so casting it to IOleClientSite is completely 
bogus.

> I then tried to call GetClientSite for the IOleObject:
>  m_OleControls[m_numControls]->GetClientSite(&temp_clientSite); 

This'll work, but it also AddRef's the client site, which explains why...

> When I passed temp_clientSite as the 3rd parameter to DoVerb everything 
seems
> fine until I exit the program.  On exiting I get an ASSERT in cmdtarg.cpp 
> at line 52.  The line is:
>   ASSERT( m_dwRef <= 1);  
> The value of m_dwRef is 2.

After calling DoVerb, be sure to Release() your temp_clientSite.

#if _MFC_VER <= 0x0410
mfcTeam.m_johnels;	// does not represent Microsoft
#endif

---

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