Knowledge Base

PRB: ActiveX Control Painting Problems in Visual C++ 4.2

Article ID: 154166

Article Last Modified on 12/1/2003

Microsoft Visual C++ 4.2 Enterprise Edition
Microsoft Visual C++ 5.0 Enterprise Edition
Microsoft Visual C++ 4.2 Professional Edition
Microsoft Visual C++ 5.0 Professional Edition

This article was previously published under Q154166

SYMPTOMS

The ActiveX (OLE) Control may not paint correctly if it was built using Visual C++ 4.2. Two known issues include controls not repainting when resized, and control child windows not being repainted. Other painting problems have been observed when subclassing native Windows controls.

CAUSE

This behavior is caused by changes to COleControl::OnPaint which add optimizations to improve performance.

RESOLUTION

COleControl now includes a method, GetControlFlags, to control how painting will be handled in an ActiveX control. Removing the fastBeginPaint flag from the bit field returned by GetControlFlags will cause your ActiveX control to use the same OnPaint code found in Visual C++ 4.1

STATUS

This behavior is by design.

MORE INFORMATION

Sample Code

DWORD CMyOleControl::GetControlFlags ()
{
   return COleControl::GetControlFlags() & ~fastBeginPaint;
}

REFERENCES

For an explanation of the GetControlFlags return values, see the documentation in Books on Line.

Additional query words: OnPaint GetControlFlags OLE 96 ocx Windowless subclassed kbSweptVC600

Keywords: kbnoupdate kbprb KB154166