Q148533: PRB: No ANSI Notifications from Control Created in OnCreate

Article: Q148533
Product(s): Microsoft C Compiler
Version(s): winnt:2.1,2.2,4.0,4.1
Operating System(s): 
Keyword(s): kbCtrl kbDlg kbDocView kbMFC KbUIDesign kbUnicode kbVC200 kbVC210 kbVC400 kbVC410 kbWnd
Last Modified: 31-JUL-2001

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The information in this article applies to:

- The Microsoft Foundation Classes (MFC), included with:
   - Microsoft Visual C++, 32-bit Editions, versions 2.1, 2.2, 4.0, 4.1 
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SYMPTOMS
========

No notification messages are received from a common control that is created in
the OnCreate function (the WM_CREATE handler) of a CFormView or CDialog. Closer
inspection reveals that notifications are being sent, but they are the UNICODE
versions of the notifications.

CAUSE
=====

The common controls send a WM_NOTIFYFORMAT message when they are first created
to determine if they should send ANSI or UNICODE notifications to the parent
window.

The default processing of WM_NOTIFYFORMAT for a dialog box returns NFR_UNICODE
until after the dialog box window has been created. At the point when the
WM_CREATE message is sent, the dialog box still returns NFR_UNICODE in response
to a WM_NOTIFYFORMAT message.

A CFormView is really a dialog box, so this is a problem for the CFormView class
as well as the CDialog class.

RESOLUTION
==========

Here are two ways to work around this problem:

- Don't create the control in the WM_CREATE handler. If the control is created
  at a later point, this problem won't occur. For a CDialog- derived class,
  create the control in the OnInitDialog function. For a CFormView-derived
  class, create the control in the OnInitialUpdate function.

  -or-

- Handle the WM_NOTIFYFORMAT message in the CDialog- or CFormView-derived class
  and respond with the NFR_ANSI code. The WM_NOTIFYFORMAT message is not
  available in ClassWizard, so you'll need to manually enter the ON_MESSAGE
  macro for the message as follows:

        BEGIN_MESSAGE_MAP(CMyDialog, CDialog)
            //{{AFX_MSG_MAP(CMyDialog)
            ... message map entries created by classwizard
            //}}AFX_MSG_MAP
            ... other manually created message map entries
            ON_MESSAGE(WM_NOTIFYFORMAT, OnNotifyFormat) // ADD THIS LINE
        END_MESSAGE_MAP()

  Add the prototype for this function to the class definition:

        class CMyDialog : public CDialog
        {
            ... other class members
        protected:
            afx_msg LRESULT OnNotifyFormat(WPARAM wParam,LPARAM lParam);
        };

  For more information on how to do this, please see the following article in
  the Microsoft Knowledge Base: ARTICLE-ID: Q99848 TITLE : Use ON_MESSAGE()
  Macro to Map Less-Common Messages The OnNotifyFormat function should be
  implemented as follows:

        LRESULT CMyDialog::OnNotifyFormat(WPARAM wParam,LPARAM lParam)
        {
          #ifdef _UNICODE
            return NFR_UNICODE;
          #else
            return NFR_ANSI;
          #endif
       }

STATUS
======

Microsoft has confirmed this to be a bug in Microsoft Windows NT. It is not a
bug in MFC. We are researching this problem and will post new information here
in the Microsoft Knowledge Base as it becomes available.

Additional query words: CAnimateCtrl CHeaderCtrl CHotKeyCtrl CImageList CListCtrl CProgressCtrl CRichEditCtrl CSliderCtrl CSpinButtonCtrl CStatusBarCtrl CTabCtrl CToolBarCtrl CToolTipCtrl CTreeCtrl 2.10 2.20 4.00 4.10 3.10 3.20 NF_QUERY NF_REQUERY

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Keywords          : kbCtrl kbDlg kbDocView kbMFC KbUIDesign kbUnicode kbVC200 kbVC210 kbVC400 kbVC410 kbWndwMsg kbGrpDSMFCATL kbDialog 
Technology        : kbAudDeveloper kbMFC
Version           : winnt:2.1,2.2,4.0,4.1
Issue type        : kbprb

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