INFO: Responding to Mouse Events with MFC ActiveX Controls
Article ID: 165020
Article Last Modified on 11/21/2006
APPLIES TO
- Microsoft Foundation Class Library 4.2, when used with:
- Microsoft Visual C++ 4.0 Standard Edition
- Microsoft Visual C++ 4.1 Subscription
- Microsoft Visual C++ 4.2 Enterprise Edition
- Microsoft Visual C++ 4.2 Professional Edition
- Microsoft Visual C++ 5.0 Enterprise Edition
- Microsoft Visual C++ 5.0 Professional Edition
- Microsoft Visual C++ 6.0 Enterprise Edition
- Microsoft Visual C++ 6.0 Professional Edition
- Microsoft Visual C++ 6.0 Standard Edition
This article was previously published under Q165020
SUMMARY
MFC-based ActiveX controls capture mouse input by calling SetCapture in
response to a mouse-button message. This can cause unexpected problems,
but the behavior is by design.
MORE INFORMATION
If you need to perform an action in response to a mouse button message
when implementing an ActiveX control, and that action involves the use of
the mouse (for example, displaying a message box or modal dialog box), you
need to perform the action after the call to the base class implementation
of the handler. Performing such actions prior to calling the base class
may result in mouse capture problems.
REFERENCES
Sample Code
void CMyButton::OnLButtonDown(UINT nFlags, CPoint point)
{
// Handle default first so that the mouse capture is resolved.
COleControl::OnLButtonDown(nFlags, point);
// Then, add your own hander code afterwards.
MessageBox(_T("No more problem!"));
}
Keywords: kbctrl kbinfo KB165020