【C#】串口操作实用类

        做工业通信有很长时间了，特别是串口（232/485)，有VB/VC/C各种版本的串口操作代码，这些代码也经过了多年的现场考验，应该说是比较健壮的代码，但是目前却没有C#相对成熟的串口操作代码，最近用Moxa的设备开发基于WinCE5.0的串口操作代码，所以就扩充完善了一下串口操作，特别是SendCommand函数，这是我比较常用的主从通信代码，不喜欢用事件或线程接数据，在规定的超时时间内直接循环判断要接收的数据。

     下面是具体的代码：   

  public class PortData
    {
        public event PortDataReceivedEventHandle Received;
        public event SerialErrorReceivedEventHandler Error; 
        public SerialPort port;
        public bool ReceiveEventFlag = false;  //接收事件是否有效 false表示有效

        public PortData(string sPortName, int baudrate,Parity parity,SerialInterface.SerialMode mode)
        {
            port = new SerialPort(sPortName, baudrate, parity, 8, StopBits.One);
            port.RtsEnable = true;
            port.ReadTimeout = 3000;
            port.DataReceived += new SerialDataReceivedEventHandler(DataReceived);
            port.ErrorReceived += new SerialErrorReceivedEventHandler(ErrorEvent);
        }

        ~PortData()
        {
            Close();
        }
        public void Open()
        {
            if (!port.IsOpen)
            {           
                port.Open();
            }
        }

        public void Close()
        {
            if (port.IsOpen)
            {
                port.Close();
            }
        }
        //数据发送
        public void SendData(byte[] data)
        {
            if (port.IsOpen)
            {
                port.Write(data, 0, data.Length);
            }
        }
        public void SendData(byte[] data,int offset,int count)
        {
            if (port.IsOpen)
            {
                port.Write(data, offset, count);
            }
        }
        //发送命令
        public int SendCommand(byte[] SendData, ref  byte[] ReceiveData,int Overtime)
        {

            if(port.IsOpen)
            {
                ReceiveEventFlag = true;        //关闭接收事件
                port.DiscardInBuffer();         //清空接收缓冲区                 
                port.Write(SendData, 0, SendData.Length);
                int num=0,ret=0;
                while (num++ < Overtime)
                {
                    if (port.BytesToRead >= ReceiveData.Length) break;
                    System.Threading.Thread.Sleep(1); 
                }
                if (port.BytesToRead >= ReceiveData.Length) 
                    ret = port.Read(ReceiveData, 0, ReceiveData.Length);
                ReceiveEventFlag = false;       //打开事件
                return ret;
            }
            return -1;
        }

        public void ErrorEvent(object sender, SerialErrorReceivedEventArgs e)
        {
            if (Error != null) Error(sender, e);
        }
        //数据接收
        public void DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            //禁止接收事件时直接退出
            if (ReceiveEventFlag) return;

            byte[] data = new byte[port.BytesToRead];
            port.Read(data, 0, data.Length);
            if (Received != null) Received(sender, new PortDataReciveEventArgs(data));
        }

        public bool IsOpen()
        {
            return port.IsOpen;
        }
    }
    public delegate void PortDataReceivedEventHandle(object sender, PortDataReciveEventArgs e);
    public class PortDataReciveEventArgs : EventArgs
    {
        public PortDataReciveEventArgs()
        {
            this.data = null;
        }

        public PortDataReciveEventArgs(byte[] data)
        {
            this.data = data;
        }

        private byte[] data;

        public byte[] Data
        {
            get { return data; }
            set { data = value; }
        }
    }

【附注】1~9 串口的名称是 "COMx:",>9的以前用////.//COMx:比较好使，但是在moxa 661设备上却不行，要用如下格式"$device//COM" + PortNo.ToString() + "/0"，也许这是moxa修改了相应的串口驱动。

//注：把代码中的public PortData(string sPortName, int baudrate,Parity parity,SerialInterface.SerialMode mode) 最后一个参数去掉。
PortData comPort = new PortData("COM1:", 115200, Parity.Even);
byte[] bytSendArray = new byte[2]; //发送数据缓冲区
bytSendArray[0]=0xAC;
bytSendArray[2]=0xAA;
byte[] bytReceiveArray = new byte[5];
//该命令潜台词是你发送了两个字节的数据0xAC,0xAA 下位机应该在200毫秒超时内返回5个字节的数据
intReceiveNum = comPort.SendCommand(bytSendData, ref bytReceiveArray, 200);
//intReceiveNum为实际返回的数据个数,返回的数据放在bytReceiveArray中
comPort.Close();
该代码适合主从式通信（一应一答方式）