FIX: CMDIFrameWnd Caption Not Updated When Child Closed (126301)

RESOLUTION

1. Derive a new MDI child window class from CMDIChildWnd, perhaps by using Class Wizard.
2. For the new class, override the DestroyWindow() function by using the following source code:

     BOOL CMyMDIChildWnd::DestroyWindow()
       {
       // Turn off the FWS_ADDTOTITLE style for the main frame window
       // if it is a maximized main frame window.
       BOOL bMaximized = (GetStyle() & WS_MAXIMIZE);
       CMDIFrameWnd* pFrameWnd = GetMDIFrame();
       DWORD dwStyle;
       if (bMaximized)
           {
           dwStyle = ::SetWindowLong(pFrameWnd->m_hWnd, GWL_STYLE,
               pFrameWnd->GetStyle() & ~FWS_ADDTOTITLE);
           }
   
       // Go ahead and destroy and MDI child window.
       BOOL bResult = CMDIChildWnd::DestroyWindow();
   
       // Restore the default window style for the main frame window.
       if (bMaximized)
           {
           ::SetWindowLong(pFrameWnd->m_hWnd, GWL_STYLE, dwStyle);
           }
   
       return bResult;
      }
   						

3. In the project .CPP file, be sure to use the newly derived MDI child window class to replace CMDIChildWnd in the CMultiDocTemplate() statement, as in this example:

       #include "mdichild.h"          // header file for CMyMDIChildWnd
   
      BOOL CMyWinApp::InitInstance()
       {
       ...
       CMultiDocTemplate* pDocTemplate;
       pDocTemplate = new CMultiDocTemplate(
           IDR_PROJECTTYPE,
           RUNTIME_CLASS(CMyDocument),
           RUNTIME_CLASS(CMyMDIChildWnd),     // use it here!!!
           RUNTIME_CLASS(CMyView));
   
       AddDocTemplate(pDocTemplate);
       ...
      }