C# 004 串口通信

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 串口通信助手2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            System.Windows.Forms.Control.CheckForIllegalCrossThreadCalls = false;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                serialPort1.PortName = comboBox1.Text;
                serialPort1.BaudRate = Convert.ToInt32(comboBox2.Text,10);//十进制数转换
                serialPort1.Open();
                button1.Enabled = false;//打开串口按钮不可用
                button2.Enabled = true;//关闭串口
            }
            catch
            {
                MessageBox.Show("端口错误，请检查串口设置","错误");
            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            for (int i = 1; i < 20; i++)
            {
                comboBox1.Items.Add("COM" + i.ToString());
            }
            comboBox1.Text = "COM1";//串口号默认值
            comboBox2.Text = "9600";//波特率默认值

            /*****************非常重要**********************/
            serialPort1.DataReceived += new SerialDataReceivedEventHandler(port_DataReceived); //处理串口对象的数据接收事件的方法.
        }

        private void port_DataReceived(Object sender, SerialDataReceivedEventArgs e)//串口数据接受时间
        {
            if (!radioButton3.Checked)//如果接收模式为字符模式
            {
                string str = serialPort1.ReadExisting();//字符串方式读
                textBox1.AppendText(str);//添加内容
            }
            else 
            {
                //如果接收模式为数值接收
                byte data;
                data = (byte)serialPort1.ReadByte();//此处需要强制类型转换，将(int)类型数据转换为byte类型数据
                string str = Convert.ToString(data, 16).ToUpper();//转换为大写十六进制字符串
                textBox1.AppendText("0x" + (str.Length == 1 ? "0" + str : str) + " ");//空补位“0"

            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            try
            {
                serialPort1.Close();//关闭串口
                button1.Enabled = true;//打开串口按钮可用
                button2.Enabled = false;//关闭窜口按钮不可用

            }
            catch(Exception err)//一般情况下关闭串口不会出错
            {
                
            }
        }

        private void button3_Click(object sender, EventArgs e)
        {
            byte[] Data = new byte[1];//只存储一个字节
            if (serialPort1.IsOpen && textBox3.Text !="")//判断串口是否打开，如果打开执行下一步操作
            {
                if (!radioButton1.Checked)//如果发送模式是字节模式
                {
                    try
                    {
                        serialPort1.WriteLine(textBox3.Text);//写数据
                    }
                    catch (Exception err)
                    {
                        MessageBox.Show("串口数据写入错误", "错误");
                        serialPort1.Close();
                        button1.Enabled = true;
                        button2.Enabled = false;
                    }
                }
                else
                {
                    for (int i = 0; i < (textBox3.Text.Length - textBox3.Text.Length % 2) / 2; i++)//取余3运算作用是防止
                    {
                        Data[0] = Convert.ToByte(textBox3.Text.Substring(i * 2, 2), 16);
                        serialPort1.Write(Data, 0, 1);//循环发送（如果输入字符为OAOBB,则发送OA,OB)

                    }
                    if (textBox3.Text.Length % 2 != 1)//剩下一维单独处理
                    {
                        Data[0] = Convert.ToByte(textBox3.Text.Substring(textBox3.Text.Length -1,1), 16);//单独发送B
                        serialPort1.Write(Data, 0, 1);//发送最后一位
                    }
                }
            }
        } 

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            textBox1.ScrollToCaret();//将滚动条调至最下
        }

    }
}