如何控制何时切换到其他图形（c++object arx）

admin1

[code]/ show "yes/no" question to user
void AsdkDataManager::documentToBeDeactivated(AcApDocument* doc)
{
   // show message      
   m_bSwitchOutToOtherDrawing = true;
   m_sFileNameBeDeactivated = _T("\0");
   CString sMsg = _T("Do you want to switch to other drawing?");
   if(AfxMessageBox(sMsg, MB_YESNO | MB_ICONQUESTION) == IDYES)
   {
      m_bSwitchOutToOtherDrawing = true; // switch to other drawing
   }
   else
   {
      m_bSwitchOutToOtherDrawing = false; // don't switch
      m_sFileNameBeDeactivated = doc->fileName();
   }
}
// reactivate previous drawing
void AsdkDataManager::documentToBeActivated(AcApDocument* doc)
{
   if (m_bSwitchOutToOtherDrawing) // switch to other drawing
   {
   }
   else //
   {
      if (!m_sFileNameBeDeactivated.IsEmpty())
      {
         AcApDocument* pDocReActive = NULL;
         getDocFromFilename(m_sFileNameBeDeactivated, pDocReActive);
         if (pDocReActive)
         {
            Acad::ErrorStatus es;
            m_bSwitchOutToOtherDrawing = true;
            m_sFileNameBeDeactivated = _T("\0");
            es = acDocManager->activateDocument(pDocReActive); // reactivate previous drawing
         }
      }
   }
}[/code]