【本文转自】http://hi.baidu.com/hexi1985/item/7919a9d67379a54cfa576841

最近在写一个上位机的监控程序用C#，如何实现串口接收数据，参考如下代码：

using System.IO.Ports;

using System.Threading;
using System.IO;

namespace SerialPortDemo
{
  public partial class Form1 : Form
  {
  bool isStar = false;
  Thread threadReceive = null;
  SerialPort serialPort = null;
  int i = 0;
  int k = 0;

  public Form1()
  {
  InitializeComponent();
  this.comboBox1.SelectedIndex = 0;
  this.comboBox2.SelectedIndex = 2;

  serialPort = new SerialPort();
  if (serialPort.IsOpen)
  serialPort.Close();
  //获得参数
  serialPort.PortName = comboBox1.SelectedItem.ToString();
  serialPort.BaudRate = int.Parse(comboBox2.SelectedItem.ToString());
  serialPort.Open();

  ThreadStart method = new ThreadStart(ReceiveData);//在线程上执行此方法
  threadReceive = new Thread(new ThreadStart(method));
  }

  private void button1_Click(object sender, EventArgs e)
  {
  try
  {
  if (button1.Text == "接收数据")
  {
  if (!isStar)//如果isStar等于true,则启动线程
  {
  threadReceive.Start();
  this.toolStripStatusLabel1.Text = "正在接收数据......";
  }
  else
  {
  threadReceive.Resume();//如果isStar等于false,则解除挂起线程
  this.toolStripStatusLabel1.Text = "暂停接收...";
  }
  button1.Text = "停止接收";
  }
  else
  {

  threadReceive.Suspend();//如果是"停止接收",则挂起线程
  button1.Text = "接收数据";
  this.toolStripStatusLabel1.Text = "暂停接收...";
  }

  }
  catch (Exception ex)
  {
  MessageBox.Show(ex.Message);
  serialPort.Close();

  }

  }
  //不断循环接收数据
  private void ReceiveData()
  {
  while (true)
  {
  Thread.Sleep(500);
  this.isStar = true;
  this.SynReceiveData();
  }
  }

  //通过串口取数据
  private void SynReceiveData()
  {
  MessageBox.Show("接收数据" + k);
  k++;
  string inputData = serialPort.ReadExisting();
  try
  {
  if (inputData != string.Empty)
  {
  if (inputData.Trim().Length == 45)
  {
  SetText(inputData);
  }
  }
  }
  catch (Exception ex)
  {
  MessageBox.Show(ex.Message);
  }

  }

  //分隔字符串并保存在指定目录下
  private void SetText(string str)
  {
  string aa = str;
  StreamWriter sw = null;

  if (aa != string.Empty)
  {
  string aaa = aa.Insert(13, ",");
  aaa = aaa.Insert(32, ",");

  String fileName = "C:\\GAJ_PUB\\kaoqin";
  if (Directory.Exists(fileName) == false)//如果目录不存在
  {
  Directory.CreateDirectory(fileName);//创建目录
  sw = File.CreateText("C:\\GAJ_PUB\\kaoqin\\person" + i + ".txt");//创建文本
  }
  else
  {
  sw = File.CreateText("C:\\GAJ_PUB\\kaoqin\\person" + i + ".txt");
  }
  sw.WriteLine(aaa);

  sw.Flush();

  sw.Close();
  i++;
  MessageBox.Show("文件已存入指定目录下!!");
  }

  }

  private void button2_Click(object sender, EventArgs e)
  {
  if (threadReceive.ThreadState==ThreadState.Running)//当前状态为启动线程
  {
  threadReceive.Abort();
  this.Close();
  }
  else if (threadReceive.ThreadState == ThreadState.Suspended)//当前状态为挂起线程
  {
  threadReceive.Resume();
  threadReceive.Abort();
  this.Close();
  }
  else if (threadReceive.ThreadState == ThreadState.SuspendRequested)//当前状态为正在挂起线程
  {
  threadReceive.Resume();
  threadReceive.Abort();
  this.Close();
  }
  else if (threadReceive.ThreadState == ThreadState.Unstarted)
  {
  this.Close();
  }
  }

  private void Form1_FormClosing(object sender, FormClosingEventArgs e)
  {
  if (threadReceive.ThreadState == ThreadState.Running)//当前状态为启动线程
  {
  threadReceive.Abort();
  this.Close();
  }
  else if (threadReceive.ThreadState == ThreadState.Suspended)//当前状态为挂起线程
  {
  threadReceive.Resume();
  threadReceive.Abort();
  this.Close();
  }
  else if (threadReceive.ThreadState == ThreadState.SuspendRequested)//当前状态为正在挂起线程
  {
  threadReceive.Resume();
  threadReceive.Abort();
  this.Close();
  }
  }

   
  }
}