1.连接串口方法

SerialPort ser = new SerialPort();//也可以在工具箱中直接拖SerialPort控件
public void OpenCom()
{
    try
    {
        //波特率
        ser.BaudRate = 9600;
        //数据位
        ser.DataBits = 8;
        ser.PortName = cbcomsmqB.Text;//端口几，例COM1
        //两个停止位
        ser.StopBits = System.IO.Ports.StopBits.One;
        //无奇偶校验位
        ser.Parity = System.IO.Ports.Parity.None;
        ser.ReadTimeout = 100;
        ser.Open();
        if (!ser.IsOpen)
        {
            MessageBox.Show("端口打开失败");
            return;
        }
        else
        {
            ToolData.WriteLog(lrtxtLog, "端口" + cbcomsmqB.Text + "打开成功", 0);
        }
        ser.DataReceived += ser_DataReceived;
    }
    catch (Exception ex)
    {
        //stop();
        serialPort2.Dispose();
        ToolData.WriteLog(lrtxtLog, ex.Message + "-----------------------", 1);
    }
}

2.事件监听方法

private void ser_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            string receive = "";//数据接收
            try
            {
                Thread.Sleep(50);  //（毫秒）等待一定时间，确保数据的完整性 int len        
                int len = serialPort2.BytesToRead;
                if (len != 0)
                {
                    byte[] buff = new byte[len];
                    ser.Read(buff, 0, len);
                    receive = Encoding.Default.GetString(buff);//数据接收内容
                }
            }
            catch
            {
                ToolData.WriteLog(lrtxtLog, "接收数据出错", 1);
                return;
            }
        }