【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)