實現SDI與MDI的轉換

如果想將一個編好的SDI應用程序轉換為MDI，首先要建立一個繼承于CMDIChidWnd的類，假設為CChldFrm，在CWinApp中作如下變化。
InitInstance()
{
. ...
    //instead of adding CSingleDocTemplate
    // Add CMultiDocTemplate.
    pDocTemplate = new CMultiDocTemplate(
           IDR_MAINFRAME,
           RUNTIME_CLASS(CSDIDoc),
           RUNTIME_CLASS(CChldFrm),
// For Main MDI Frame change this frame window from
// CFrameWnd derivative ( i.e. CMainFrame )
// to your CMDIChildWnd derived CChldFrm.
           RUNTIME_CLASS(CSDIView));
/// After this it is required to create the main frame window
// which will contain all the child windows. Now this window is
// what was initially frame window for SDI.
    CMainFrame* pMainFrame = new CMainFrame;
    if (!pMainFrame->LoadFrame(IDR_MAINFRAME))
            return FALSE;
     m_pMainWnd = pMainFrame;
.....
}
在從CMDIFrameWnd中繼承的類CMainFrame代替CFramWnd后，所有的類都將從CMDIFrame繼承，而不是CFrameWnd,編譯運行后你就會發現程序已經從SDI變換到MDI。
注意：在CMainFram中必須將構造函數從private改為public.否則會出錯。

原文轉自：http://www.anti-gravitydesign.com