Byte DataRecTemp = 0;
  

  Byte[] DataTest = new Byte[1];
  

  int DataCount = 0;
  

  string[] ports = System.IO.Ports.SerialPort.GetPortNames();
  

  foreach(string port in ports){
  

  serialPort.PortName = port;
  

  serialPort.BaudRate = 9600;
  

  MessageBox.Show(port);
  

  try
  

  {
  

  serialPort.Open();
  

  if (serialPort.IsOpen)
  

  {
  

  DataTest[0] = 0xFF;
  

  serialPort.Write(DataTest, 0, 1);
  

  while (DataCount < 5)
  

  {
  

  

  DataRecTemp = Convert.ToByte(serialPort.ReadByte());
  

  if (DataRecTemp == 0x55)
  

  {
  

  DataCount++;
  

  }
  

  else
  

  {
  

  break;
  

  }
  

  }
  

  if (DataCount == 5)
  

  {
  

  MessageBox.Show("可行");
  

  break;
  

  }
  

  else
  

  {
  

  MessageBox.Show("不可行");
  

  serialPort.Close();
  

  }
  

  }
  

  }
  

  catch
  

  {
  

  MessageBox.Show("未知错误!");
  

  }
  

  

  

  }