关于MFC中的异常

这是MSDN中的一个示例，我觉得很不错，想查看的朋友可以在MSDN中搜索delete即可。

CFile* pFile = NULL;

  // Constructing a CFile object with this override may throw
  // a CFile exception, and won't throw any other exceptions.
  // Calling CString::Format() may throw a CMemoryException,
  // so we have a catch block for such exceptions, too. Any
  // other exception types this function throws will be
  // routed to the calling function.

  // Note that this example performs the same actions as the
  // example for CATCH, but uses C++ try/catch syntax instead
  // of using the MFC TRY/CATCH macros. This sample must use
  // CException::Delete() to delete the exception objects
  // before closing the catch block, while the CATCH example
  // implicitly performs the deletion via the macros.

  try
  {
     pFile = new CFile(_T("C://WINDOWS//SYSTEM.INI"),
        CFile::modeRead | CFile::shareDenyNone);

     DWORD dwLength = pFile->GetLength();

     CString str;
     str.Format(_T("Your SYSTEM.INI file is %u bytes long."),
        dwLength);

     AfxMessageBox(str);
  }
  catch(CFileException* pEx)
  {
     // Simply show an error message to the user.

     pEx->ReportError();
     pEx->Delete();
  }
  catch(CMemoryException* pEx)
  {
     // We can't recover from this memory exception, so we'll
     // just terminate the app without any cleanup. Normally, an
     // an application should do everything it possibly can to
     // clean up properly and _not_ call AfxAbort().

     pEx->Delete();
     AfxAbort();
  }

  // If an exception occurrs in the CFile constructor,
  // the language will free the memory allocated by new
  // and will not complete the assignment to pFile.
  // Thus, our clean-up code needs to test for NULL.

  if (pFile != NULL)
  {
     pFile->Close();
     delete pFile;