// 关闭读写器
 private void 关闭读写器()
 {
     if (reader != null)
     {
         reader.DisConnect();
         reader = null;
     }
 }
 // 关闭读写器
 private void 关闭读写器()
 {
     if (_reader != null)
     {
         _reader.DisConnect();
         _isConnected = false;
         _reader      = null;
     }
 }