FIX: Assert in AtlCtl.cpp, Line 121

• The Microsoft Active Template Library (ATL), versions 2.0, 2.1, used with:
  • Microsoft Visual C++, 32-bit Editions, versions 4.2b, 5.0

SYMPTOMS

When you insert a debug version of your ATL control into a control container like Visual Basic, you might get an assert in AtlCtl.cpp, line The assert occurs in the CComControlBase::IQuickActivate_QuickActivate() method that checks whether the cbSize member of the QACONTAINER structure is equal to sizeof(QACONTAINER):

   _ASSERTE(pQACont->cbSize >= sizeof(QACONTAINER)); 

CAUSE

The container initializes the QACONTAINER structure and passes it into the control using IQuickActivate::QuickActivate(). QACONTAINER is defined in Ocidl.h that comes with both Visual C++ and the Platform SDK. However, the Platform SDK provides a newer version of QACONTAINER that includes two additional interface pointers. Therefore, the QACONTAINER passed in by the container doesn't match the size of the QACONTAINER defined in the newer Ocidl.h.

RESOLUTION

The assert is harmless and can be ignored. Or, you can get rid of the assert by performing the following steps:

1. Override IQuickActivate::QuickActivate().



2. Copy the contents of CComControlBase::IQuickActivate_QuickActivate() into your override of IQuickActivate::QuickActivate().



3. Comment out the assert.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This problem was corrected in Visual C++ version 6.0 for Windows.

Additional query words: kbCtrl kbATL200bug kbATL210bug kbVC420 kbVC500 kbvc600fix

Keywords : kbnokeyword kbActiveX kbATL200bug kbATL210bug kbCOMt kbContainer kbCtrlCreate kbDebug kbVBp kbVC420bug kbVC500bug kbVC600fix kbATL300fix kbGrpMFCATL
Version : WINDOWS:2.0,2.1
Platform : WINDOWS
Issue type : kbbug