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Q189382: PRB: CWnd::m_nMsgDragList Not Exported by the MFC DLL

Article: Q189382
Product(s): Microsoft C Compiler
Version(s): winnt:5.0
Operating System(s): 
Keyword(s): kbnokeyword kbDLL kbMFC kbVC500 kbGrpDSMFCATL kbArchitecture
Last Modified: 17-JUL-2001

-------------------------------------------------------------------------------
The information in this article applies to:

- The Microsoft Foundation Classes (MFC), used with:
   - Microsoft Visual C++, 32-bit Enterprise Edition, version 5.0 
   - Microsoft Visual C++, 32-bit Professional Edition, 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.
(c) Microsoft Corporation 1998, All Rights Reserved.
Contributions by Isaac L. Varon, Microsoft Corporation


Additional query words:

======================================================================
Keywords          : kbnokeyword kbDLL kbMFC kbVC500 kbGrpDSMFCATL kbArchitecture 
Technology        : kbAudDeveloper kbMFC
Version           : winnt:5.0
Issue type        : kbprb

=============================================================================

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