HOWTO: Change Window Background Color with Foundation Classes

The information in this article applies to:

• The Microsoft Foundation Classes (MFC) included with:

      - Microsoft Visual C++ for Windows, versions 1.0, 1.5, 1.51, 1.52
      - Microsoft Visual C++, 32-bit Edition, version 1.0, 2.0, 2.1, 4.0
  

SUMMARY

To change the background color for a CView, CFrameWnd, or CWnd object, process the WM_ERASEBKGND message. The sample code below demonstrates how to do this.

MORE INFORMATION

Sample Code

   BOOL CSampleView::OnEraseBkgnd(CDC* pDC)
   {
      // Set brush to desired background color
      CBrush backBrush(RGB(255, 128, 128));

      // Save old brush
      CBrush* pOldBrush = pDC->SelectObject(&backBrush);

      CRect rect;
      pDC->GetClipBox(&rect);     // Erase the area needed

      pDC->PatBlt(rect.left, rect.top, rect.Width(), rect.Height(),
          PATCOPY);
      pDC->SelectObject(pOldBrush);
      return TRUE;
   }

    ARTICLE-ID: Q129471
    TITLE     : HOWTO: Subclass the MDICLIENT by Using MFC

1. Create a generic CWnd class with ClassWizard.

2. Add a member variable, using the type of the CWnd class from step 1, to the CMainFrame class.

3. In the CMainFrame's OnCreate member function, after the call to the base class CMDIFrameWnd::OnCreate(), add a call to SubclassWindow(). For example:

         if (!m_wndNewClient.SubclassWindow(m_hWndMDIClient))
         {
           TRACE("Failed to subclass MDI client window\n");
           return -1;      // fail to create
         }
   
      m_hWndMDIClient is the member variable of CMDIFrameWnd that
      contains the handle to the MDI client window. Also, replace
      "m_wndNewClient" with the data member that you created in step 2.
   
   

4. Whenever a window is subclassed, the GetSuperWndProcAddr() member function for the CWnd needs to be overridden to provide storage for the old window procedure's address. To do that, add the following function to the implementation of the CWnd class created in step 1:

         WNDPROC* CNewClientWnd::GetSuperWndProcAddr()
         {
            static WNDPROC NEAR pfnSuper = NULL;
            return &pfnSuper;
         }
   
      NOTE: Replace "CNewClientWnd" above with the name of your class.
   
      For more information on subclassing windows using the Microsoft
      Foundation Classes, please see the following materials:
   
      - "Class Library Reference" for functions CWnd::SubclassWindow(),
        CWnd::GetSuperWndProcAddr(), and CWnd::SubclassDlgItem()
   
      - Query on the following words in the Microsoft Knowledge Base:
   
        subclass and sample and mfc
   
      - See the CTRLTEST MFC sample application that is provided with
        Visual C++ for Windows and Visual C++ 32-bit Edition.
   
      - See the article titled "Subclassing Windows with the Microsoft
        Foundation Class Library" on the Microsoft Developer Network
        (MSDN) CD.
   
   

5. Override the WM_ERASEBKGND message for the generic CWnd class, using the code listed above.

For more information on changing the background color of a dialog box by processing the WM_CTLCOLOR message, please query on the following words in the Microsoft Knowledge Base: