KB183210 - An ATL control may flicker when it is being resized in Visual C++

Article ID: 183210

Article Last Modified on 6/3/2005

Microsoft ActiveX Template Library 3.0, when used with:
- Microsoft Visual C++ 4.2 Enterprise Edition
- Microsoft Visual C++ 5.0 Enterprise Edition
- Microsoft Visual C++ 6.0 Enterprise Edition
- Microsoft Visual C++ 4.2 Professional Edition
- Microsoft Visual C++ 5.0 Professional Edition
- Microsoft Visual C++ 6.0 Professional Edition
- Microsoft Visual C++ 6.0 Standard Edition
- Microsoft Windows XP Home Edition
- Microsoft Windows XP Professional
- Microsoft Visual C++ .NET 2002 Standard Edition
- Microsoft Visual C++ .NET 2003 Standard Edition
Microsoft ActiveX Template Library 2.0, when used with:
- Microsoft Visual C++ 4.2 Enterprise Edition
- Microsoft Visual C++ 5.0 Enterprise Edition
- Microsoft Visual C++ 6.0 Enterprise Edition
- Microsoft Visual C++ 4.2 Professional Edition
- Microsoft Visual C++ 5.0 Professional Edition
- Microsoft Visual C++ 6.0 Professional Edition
- Microsoft Visual C++ 6.0 Standard Edition
- Microsoft Windows XP Home Edition
- Microsoft Windows XP Professional
- Microsoft Visual C++ .NET 2002 Standard Edition
- Microsoft Visual C++ .NET 2003 Standard Edition
Microsoft ActiveX Template Library 2.1, when used with:
- Microsoft Visual C++ 4.2 Enterprise Edition
- Microsoft Visual C++ 5.0 Enterprise Edition
- Microsoft Visual C++ 6.0 Enterprise Edition
- Microsoft Visual C++ 4.2 Professional Edition
- Microsoft Visual C++ 5.0 Professional Edition
- Microsoft Visual C++ 6.0 Professional Edition
- Microsoft Visual C++ 6.0 Standard Edition
- Microsoft Windows XP Home Edition
- Microsoft Windows XP Professional
- Microsoft Visual C++ .NET 2002 Standard Edition
- Microsoft Visual C++ .NET 2003 Standard Edition

This article was previously published under Q183210

SYMPTOMS

An ATL control might flicker while it is being resized. For example, if you have a ListView control inside an ATL control and you allow it to be resized at run time, a significant amount of flickering occurs.

CAUSE

ATL controls are created by default with the CS_HREDRAW and CS_VREDRAW class styles. These styles cause the entire window to be redrawn when the window is resized.

RESOLUTION

Remove the CS_HREDRAW and CS_VREDRAW styles from the window by overriding the GetWndClassInfo() function. Add the following function to your CComControl-derived class:

Sample Code

static CWndClassInfo& GetWndClassInfo()
{
   static CWndClassInfo wc = {{ sizeof(WNDCLASSEX), 0, StartWindowProc,
   0, 0, 0, 0, 0, (HBRUSH)(COLOR_WINDOW+1), 0, "MyControlClass", 0 },
   NULL, NULL, IDC_ARROW, TRUE, 0, _T("")};
   return wc;
}

STATUS

This behavior is by design.

MORE INFORMATION

GetWndClassInfo() is called by the CWindowImpl<>::Create() method during window creation and uses the WNDCLASS structure initialized by GetWndClassInfo().

Additional query words: WM_PAINT OnPaint OnDraw WM_SIZE OnSize SetObjectRects Invalidate InvalidateRect FireViewChange kbATL200 kbATL210 kbATL300 kbctrl

Keywords: kbtshoot kbctrlcreate kbgdi kbprb KB183210