C# 串口通信

串口通信程序是很多需要了解的,作为一个新手,按照网上的教程编写成功了,所以准备写下来保存,也许也能帮到别人,觉得这是一件很有意义的事。言归正传,这是窗口应用程序,下面图片是利用窗口控件所设计的界面。主要就是了解一下串口通信的机制。主要能够实现发送数据和接收数据的功能。控件不熟悉的就去网上查找和学习。

下面是源代码:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO.Ports;

namespace SerialPortTest
{
  public partial class Form1 : Form
  {
    public Form1()
    {
      InitializeComponent();
    }

    SerialPort sp1 = new SerialPort();        //这个是定义的全局变量;
    private void Form1_Load(object sender, EventArgs e)        //窗体加载
    {          
      string[] str = SerialPort.GetPortNames();//检查是否含有串口 
      if (str == null)
      {
        MessageBox.Show("本机没有串口!", "Error");
        return;
      }

      foreach (string s in System.IO.Ports.SerialPort.GetPortNames())   //添加串口
      {
        cbSerial.Items.Add(s);          //获取有多少个COM口,添加到控件里
      }
      cbBaudRate.Items.Add("9600"); //对波特率,数据位,停止伟这几个控件里面的值进行初始化显示 这样就可以避免我们调试时反复的对他们进行输入
      cbDataBits.Items.Add("8");
      cbStop.Items.Add("1");
      cbParity.Items.Add("无");     

      cbSerial.SelectedIndex = 0; //获取或是指当前选定项的索引//串口设置默认选择项 
      cbBaudRate.SelectedIndex = 0;
      cbDataBits.SelectedIndex = 0;
      cbStop.SelectedIndex = 0;
      cbParity.SelectedIndex = 0;
      radio1.Checked = true;    //发送数据的“16进制”单选按钮 
      rbRcvStr.Checked = true;

      Control.CheckForIllegalCrossThreadCalls = false;
      sp1.DataReceived += new SerialDataReceivedEventHandler(sp1_DataReceived); //订阅委托
    }

    private void btnSwitch_Click(object sender, EventArgs e)
    {
      //SerialPort sp1 = new SerialPort();
      if (!sp1.IsOpen)
      {
        try
        {
          string serialName = cbSerial.SelectedItem.ToString();//设置串口号 
          sp1.PortName = serialName;

          //设置各“串口设置”
          string strBaudRate = cbBaudRate.Text;
          string strDateBits = cbDataBits.Text;
          string strStopBits = cbStop.Text;
          Int32 iBaudRate = Convert.ToInt32(strBaudRate);
          Int32 iDateBits = Convert.ToInt32(strDateBits);

          sp1.BaudRate = iBaudRate; //波特率
          sp1.DataBits = iDateBits; //数据位
          switch (cbStop.Text) //停止位
          {
            case "1":
            sp1.StopBits = StopBits.One;
            break;
            case "1.5":  
            sp1.StopBits = StopBits.OnePointFive;
            break;
            case "2":
            sp1.StopBits = StopBits.Two;
            break;
            default:
            MessageBox.Show("Error:参数不正确!", "Error");
            break;
          }
          switch (cbParity.Text) //校验位
          {
            case "无":
            sp1.Parity = Parity.None;
            break;
            case "奇校验":
            sp1.Parity = Parity.Odd;
            break;
            case "偶校验":
            sp1.Parity = Parity.Even;
            break;
            default:
            MessageBox.Show("Error:参数不正确!", "Error");
            break;
          }

          if (sp1.IsOpen == true)//如果打开状态,则先关闭一下
          {
            sp1.Close();
          }
          //状态栏设置
          tsSpNum.Text = "串口号:" + sp1.PortName + "|";
          tsBaudRate.Text = "波特率:" + sp1.BaudRate + "|";
          tsDataBits.Text = "数据位:" + sp1.DataBits + "|";
          tsStopBits.Text = "停止位:" + sp1.StopBits + "|";
          tsParity.Text = "校验位:" + sp1.Parity + "|";

          //设置必要控件不可用
          cbSerial.Enabled = false;
          cbBaudRate.Enabled = false;
          cbDataBits.Enabled = false;
          cbStop.Enabled = false;
          cbParity.Enabled = false;

          sp1.Open(); //打开串口
          btnSwitch.Text = "关闭串口";
          }
          catch (System.Exception ex)
          {
             MessageBox.Show("Error:" + ex.Message, "Error");
             return;
          }
      }
      else
      {
        //状态栏设置
        tsSpNum.Text = "串口号:未指定|";
        tsBaudRate.Text = "波特率:未指定|";
        tsDataBits.Text = "数据位:未指定|";
        tsStopBits.Text = "停止位:未指定|";
        tsParity.Text = "校验位:未指定|";


        //恢复控件功能
        //设置必要控件不可用
        cbSerial.Enabled = true;
        cbBaudRate.Enabled = true;
        cbDataBits.Enabled = true;
        cbStop.Enabled = true;
        cbParity.Enabled = true;

        sp1.Close(); //关闭串口
        btnSwitch.Text = "打开串口";
      }
    }

    private void btnSend_Click(object sender, EventArgs e) //等待修改
    {
      if (!sp1.IsOpen) //如果没打开
      {
        MessageBox.Show("请先打开串口!", "Error");
        return;
      }   

      String strSend = txtSend.Text;
      if (radio1.Checked == true) //“16进制发送” 按钮
      {
        //处理数字转换,目的是将输入的字符按空格、“,”等分组,以便发送数据时的方便(此处转的比较麻烦,有高见者,请指点!)
        string sendBuf = strSend;
        string sendnoNull = sendBuf.Trim();
        string sendNOComma = sendnoNull.Replace(',', ' '); //去掉英文逗号
        string sendNOComma1 = sendNOComma.Replace(',', ' '); //去掉中文逗号
        string strSendNoComma2 = sendNOComma1.Replace("0x", ""); //去掉0x
        strSendNoComma2.Replace("0X", ""); //去掉0X
        string[] strArray = strSendNoComma2.Split(' ');
        int byteBufferLength = strArray.Length;
        for (int i = 0; i <strArray.Length;i++)
        {
          if (strArray[i]=="")
          {  
            byteBufferLength--;
          }
        }

        byte[] byteBuffer = new byte[byteBufferLength];
        int ii = 0;
        for (int i = 0; i < strArray.Length; i++) //对获取的字符做相加运算
        {
          Byte[] bytesOfStr = Encoding.Default.GetBytes(strArray[i]);
          int decNum = 0;
          if (strArray[i] == "")
          {   
            continue;     
          }        
          else
          {
            decNum = Convert.ToInt32(strArray[i], 16); //strArray[i] == 12时,temp == 18
          }
          try //防止输错,使其只能输入一个字节的字符,即只能在txtSend里输入 “eb 90”等字符串,不能输入“123 2345”等超出字节范围的数字
          {
            byteBuffer[ii] = Convert.ToByte(decNum);
          }
          catch (System.Exception ex)
          {
            MessageBox.Show("字节越界,请逐个字节输入!", "Error");
            return;
          }
        ii++;
      }
      sp1.Write(byteBuffer, 0, byteBuffer.Length);
      }
      else //以字符串形式发送时
      {
        sp1.WriteLine(txtSend.Text); //写入数据
      }
    }
    void sp1_DataReceived(object sender, SerialDataReceivedEventArgs e)
    {
      if (sp1.IsOpen) //严谨性
      {
        byte[] byteRead = new byte[sp1.BytesToRead]; //BytesToRead:sp1接收的字符个数
        if (radio2.Checked) //'发送字符串'单选按钮
        {
          txtRcv.Text += sp1.ReadLine() + " "; //注意:回车换行必须这样写,单独使用" "和" "都不会有效果
          sp1.DiscardInBuffer(); //清空SerialPort控件的Buffer
        }
        else //'发送16进制按钮'
        {
          try
          {
            Byte[] receivedData = new Byte[sp1.BytesToRead]; //创建接收字节数组
            sp1.Read(receivedData, 0, receivedData.Length); //读取数据
            sp1.DiscardInBuffer(); //清空SerialPort控件的Buffer
            string strRcv = null;  
            for (int i = 0; i < receivedData.Length; i++) //窗体显示
            {

              strRcv += receivedData[i].ToString("X2"); //16进制显示
            }
            txtRcv.Text += strRcv + " ";
          }
          catch (System.Exception ex)
          {
            MessageBox.Show(ex.Message, "出错提示");
            txtSend.Text = "";
          }
        }
      }
      else
      {
        MessageBox.Show("请打开某个串口", "错误提示");
      }
      DateTime dt = DateTime.Now;
      //txtRcv.Text += dt.GetDateTimeFormats('f')[0].ToString() + " ";
      //txtRcv.SelectAll();
      //txtRcv.SelectionColor = Color.Blue; //改变字体的颜色
    }

    private void btnClear_Click(object sender, EventArgs e)
    {
      //comboBox1.Items.Clear();
      txtRcv.Clear();
      // foreach (Control ctrl in Controls)//或为groupBox1.Controls/panel1.Controls 可以做判断
      //{
        // if (ctrl is TextBox)
        // ctrl.Text = "";
      //}
    }

    private void btnExit_Click(object sender, EventArgs e)
    {
      Application.Exit();
    }
  }
}  

原文地址:https://www.cnblogs.com/shuaiheng/p/7443992.html