如何实现SDI与MDI的转换？

如果想将一个编好的SDI应用程序转换为MDI，首先要建立一个继承于CMDIChidWnd的类，假设为CChldFrm，在CWinApp中作如下变化。 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; ..... } 在从CMDIFrameWnd中继承的类CMainFrame代替CFramWnd后，所有的类都将从CMDIFrame继承，而不是CFrameWnd,编译运行后你就会发现程序已经从SDI变换到MDI。 注意：在CMainFram中必须将构造函数从private改为public.否则会出错。