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。
