FIX: Advanced Options for SDI Application in Appwizard

• The Microsoft Foundation Classes (MFC), included with:
  • Microsoft Visual C++, 32-bit Editions, versions 2.0, 2.1, 2.2, 4.0, 4.1, 4.2

SYMPTOMS

Some of the Advance Options in Step 4 of AppWizard have no effect on an AppWizard-generated SDI applications. The Maximized and Minimized options for the Main Frame Window in the Window Styles tab have no effect when selected for an SDI application.

The message generated in Visual C++ version 4.0, 4.1, or 4.2 that says these styles have no effect on Windows 95 is also wrong. The problem isn't specific to Windows 95.

CAUSE

The AppWizard-generated code does not have code to show the main window maximized or minimized. MFC code shows the main window with value passed into the program through the nCmdShow argument to WinMain. This value is normally SW_NORMAL and hence the window will not be maximized or minimized.

RESOLUTION

MFC stores the value passed through the nCmdShow argument to WinMain in CWinApp::m_nCmdShow. This variable can be modified to get the behavior you want. To have an SDI application initially maximized or minimized, set this variable to the appropriate value. Set m_nCmdShow to SW_SHOWMAXIMIZED to maximize or SW_SHOWMINIMIZED to minimize the main frame window initially. This variable has to be modified in the InitInstance() function of the CWinApp-derived class before the main window is made visible.

In the Visual C++ 4.0 or 4.1 AppWizard-generated application, set this variable before this line:

   if (!ProcessShellCommand(cmdInfo))
      return FALSE; 

   OnFileNew(); 

    if  (!ProcessShellCommand(cmdInfo))
        return FALSE;

    m_pMainWnd->ShowWindow(SW_SHOWMAXIMIZED); 

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. The problem was corrected in Visual C++ version 5.0.

MORE INFORMATION

The following sample code shows the correct context in which m_nCmdShow has to be modified and demonstrates how to show an sdi application initially maximized.

Sample Code

   // Visual C++ 4.0, 4.1, or 4.2 AppWizard-generated SDI application
   BOOL CMyApp::InitInstance()
   {
   ...
      ParseCommandLine(cmdInfo);

           // Add the following line to initially maximize the Application.
           m_nCmdShow = SW_SHOWMAXIMIZED;

      // Dispatch commands specified on the command line.
      if (!ProcessShellCommand(cmdInfo))
         return FALSE;

      return TRUE;
   }

   // Visual C++ 2.0 AppWizard-generated SDI application.
   BOOL CMyApp::InitInstance()
   {
   ...
      AddDocTemplate(pDocTemplate);

           // Add the following line to initially maximize the Application.
           m_nCmdShow = SW_SHOWMAXIMIZED;

      // Create a new (empty) document
      OnFileNew();
   ...
   } 

Additional query words: kbVC400bug

Keywords : kbnokeyword kbwizard kbMFC kbVC kbVC500fix
Version : 2.0 2.1 2.2 4.0 4.1 4.2
Platform : NT WINDOWS
Issue type : kbbug