如何从一个对话框弹出单文档视图

BOOL CDlgTestApp::InitInstance()
{
       AfxEnableControlContainer();
 
       // Standard initialization
       // If you are not using these features and wish to reduce the size
       //  of your final executable, you should remove from the following
       //  the specific initialization routines you do not need.
 
#ifdef _AFXDLL
       Enable3dControls();                     // Call this when using MFC in a shared DLL
#else
       Enable3dControlsStatic();      // Call this when linking to MFC statically
#endif
 
       // Change the registry key under which our settings are stored.
       // TODO: You should modify this string to be something appropriate
       // such as the name of your company or organization.
       SetRegistryKey(_T("Local AppWizard-Generated Applications"));
 
       LoadStdProfileSettings();  // Load standard INI file options (including MRU)
 
       // Register the application‘s document templates.  Document templates
       //  serve as the connection between documents, frame windows and views.
 
CLogsys  TestDlg;
if(TestDlg.DoModal()==IDOK)   // 单击Ok后就开始初始化程序实例
{
    CSingleDocTemplate* pDocTemplate;
       pDocTemplate = new CSingleDocTemplate(
              IDR_MAINFRAME,
              RUNTIME_CLASS(CDlgTestDoc),
              RUNTIME_CLASS(CMainFrame),       // main SDI frame window
              RUNTIME_CLASS(CDlgTestView));
       AddDocTemplate(pDocTemplate);
    // Parse command line for standard shell commands, DDE, file open
       CCommandLineInfo cmdInfo;
       ParseCommandLine(cmdInfo);
 
       // Dispatch commands specified on the command line
       if (!ProcessShellCommand(cmdInfo))
              return FALSE;
       // The one and only window has been initialized, so show and update it.
       m_pMainWnd->ShowWindow(SW_SHOW);
       m_pMainWnd->UpdateWindow();
    return TRUE;
}
else    // 假如单击了CANCEL按钮就直接退出
        return FALSE;
 
}

void CLogsys::OnOK()
{
       // TODO: Add extra validation here
UpdateData(TRUE);  // 获取输入数据
if(m_strUser=="Admin"&&m_strPwd=="1234")
{
CDialog::OnOK();  // 假如用户名和密码正确，就关闭对话框
}
/*假如用户名或密码错误，且还未超出登陆次数，就进行提示*/
if((m_strUser!="Admin"||m_strPwd!="1234")&&(m_Time<3)) //假如密码和用户名正确
   {
AfxMessageBox("用户名或密码不正确");
m_Time++;
   }
/*假如超出登陆次数，提示并退出系统*/
if(m_Time>2)
   {
AfxMessageBox("登陆错误次数超过3次");
PostQuitMessage(0);
   }
}