PRB: CWnd::m_nMsgDragList Not Exported by the MFC DLL

• The Microsoft Foundation Classes (MFC), included with:
  • Microsoft Visual C++, 32-bit Editions, version 5.0

SYMPTOMS

When you use the protected CWnd member m_nMsgDragList in an application or DLL that is linked to the MFC shared DLL, a LNK2001 unresolved external error occurs.

This error does not occur when you link to the static MFC library.

CAUSE

CWnd::m_nMsgDragList is not exported from the MFC DLL.

RESOLUTION

To workaround this problem, call RegisterWindowMessage with the DRAGLISTMSGSTRING message and use the value returned instead of CWnd::m_nMsgDragList. For example:

   UINT nMsgDragList = ::RegisterWindowMessage(DRAGLISTMSGSTRING); 

STATUS

This behavior is by design.

MORE INFORMATION

CWnd::m_nMsgDragList is an undocumented member of the CWnd class and is subject to change. The most common use of CWnd::m_nMsgDragList occurs when you override OnChildNotify in a CWnd derived class.

© Microsoft Corporation 1998, All Rights Reserved.
Contributions by Isaac L. Varon, Microsoft Corporation

Additional query words: kbMFC kbVC500

Keywords :
Version : winnt:5.0
Platform : winnt
Issue type : kbprb