DOCUMENT:Q131989 29-JUL-2001 [visualc] TITLE :PRB: PreCreateWindow() Not Called for CFormView PRODUCT :Microsoft C Compiler PROD/VER:winnt:1.0,2.0,2.1 OPER/SYS: KEYWORDS:kbnokeyword kbMFC kbVC100 kbVC150 kbVC200 kbVC400 kbprb kbGrpDSMFCATL ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - The Microsoft Foundation Classes (MFC), used with: - Microsoft Visual C++ for Windows, 16-bit edition, versions 1.0, 1.5, 1.51, 1.52 - Microsoft Visual C++, 32-bit Editions, versions 1.0, 2.0, 2.1 ------------------------------------------------------------------------------- SYMPTOMS ======== PreCreateWindow() for a CFormView derived class does not get called by the MFC framework during the creation process of a formview. CAUSE ===== This is by design. During the creation of the view, the view's Create() function is called by the framework. This then calls CWnd::Create for all the views except CFormView. The CFormView class has its own Create, which calls ::CreateDialog to create the view. CWnd::Create has a call to PreCreateWindow while CFormView::Create does not. As a result, PreCreateWindow( ) for a CFormView derived class does not get called. RESOLUTION ========== To change the initial size and location, override the frame window's PreCreateWindow(). To make other changes, override the virtual function, CFormView::Create(). STATUS ====== This behavior is by design. MORE INFORMATION ================ PreCreateWindow() is generally used to alter the default values of the CREATESTRUCT structure before the window is created. This structure contains fields that determine the initial size, location, style, and class among other properties for the window. For CView derived objects, the size, location, and some of the style bits have no effect when modified. In general, the encapsulating frame window's PreCreateWindow() should be overridden and used instead. However, if you need to change the view's CREATESTRUCT, you can override PreCreateWindow() for the view, except for the CFormView (and CRecordView) class. CFormView (and CRecordView) uses the dialog template to initialize most of its window properties. As a result, CFormView::Create() calls ::CreateDialog(), passing it the dialog template resource as one of its parameters. CView, CEditView, and CScrollView call CWnd::Create() which calls CWnd::CreateEx() where the CREATESTRUCT structure is filled and PreCreateWindow() is called before ::CreateWindowEx(). Typically, there is very little flexibility in changing the default construction parameters for a CFormView after the creation process has started. Some of the parameters that can be modified by PreCreateWindow for other views, like the class name, are ignored in the case of CFormView. See the implementation of CFormView::Create in the Viewform.cpp file for more details. NOTE: Starting with MFC version 4.0, included with Visual C++ version 4.0, CFormView::Create() calls its PreCreateWindow() to get the prefered extended style. This is done before the modeless dialog is created. REFERENCES ========== For more information, please see the MFC source library and Online Books. Additional query words: 1.00 1.50 2.00 2.10 ====================================================================== Keywords : kbnokeyword kbMFC kbVC100 kbVC150 kbVC200 kbVC400 kbprb kbGrpDSMFCATL Technology : kbAudDeveloper kbMFC Version : winnt:1.0,2.0,2.1 Issue type : kbprb ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.