Microsoft KB Archive/149982

= BUG: GetDlgItem Returns NULL Under Win32s =

Article ID: 149982

Article Last Modified on 11/21/2006

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APPLIES TO

 Microsoft Foundation Class Library 4.2, when used with:  Microsoft Visual C++ 4.0 Standard Edition

 Microsoft Visual C++ 4.1 Subscription 

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This article was previously published under Q149982



SYMPTOMS
Calling GetDlgItem to get the CWnd pointer of a control in a dialog can fail and return NULL under Win32s. DoDataExchange, which calls DDX functions, also ends up calling GetDlgItem. This can result in an assert in Dlgdata.cpp, line 43.



CAUSE
This is caused by having extended styles in any of the controls in the dialog. Any extended style converts the dialog resource to a DIALOGEX resource. Win32s does not support DIALOGEX resources. None of the controls in the dialog are be created and the dialog does not display correctly. For details on how to replace the DIALOGEX style, please see the "More Information" section of this article.



RESOLUTION
Remove all extended styles in all the controls in the dialog resource.

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STATUS
Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching the problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

Visual C++ versions 4.2 and later do not support building Win32s applications.

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MORE INFORMATION
For additional information, please see the following article in the Microsoft Knowledge Base:

138971 BUG: Default Dialog-Based Application Doesn't Work in Win32s

Additional query words: Dialog based hangs

Keywords: kbbug kbdlg kbprogramming kbuidesign KB149982

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