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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