C# 串口接收

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

namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            CheckForIllegalCrossThreadCalls = false;
            
            serialPort1.DataReceived += new SerialDataReceivedEventHandler(port_DataReceived);
            serialPort1.Encoding = Encoding.GetEncoding("GB2312");
            System.Windows.Forms.Control.CheckForIllegalCrossThreadCalls = false;
        }


        /// /数据接收部分
        private void port_DataReceived(object sender, SerialDataReceivedEventArgs e)//接收函数
          
        {
            try
            {
   
                string recive_data;
                recive_data = serialPort1.ReadExisting();
                recive_data = returnData.ToString();
                textBox1.Text += recive_data;
                textBox1.AppendText("\r\n");
            }
            catch { }
        }

     

        /// //搜索串口部分
        private void button1_Click(object sender, EventArgs e)
        {
            SearchAnAddSerialToComboBox(serialPort1, comboBox1);
        }
        private void SearchAnAddSerialToComboBox(SerialPort MyPort, ComboBox MyBox)//搜索串口函数
        { //将可用的串口号添加到ComboBox
            string[] NmberOfport = new string[20];//最多容纳20个，太多会卡，影响效率
            string MidString1;//中间数组，用于缓存
            MyBox.Items.Clear();//清空combobox的内容
            for (int i = 1; i < 20; i++)
            {
                try //核心是靠try和catch 完成遍历
                {
                    MidString1 = "COM" + i.ToString();  //把串口名字赋给MidString1
                    MyPort.PortName = MidString1;       //把MidString1赋给 MyPort.PortName 
                    MyPort.Open();                      //如果失败，后面代码不执行？？
                    NmberOfport[i - 1] = MidString1;    //依次把MidString1的字符赋给NmberOfport
                    MyBox.Items.Add(MidString1);        //打开成功，添加到下列列表
                    MyPort.Close();                     //关闭
                    MyBox.Text = NmberOfport[i - 1];    //显示最后扫描成功那个串口
                }
                catch { };
            }
        }
  
        /// 打开串口部分
        private void button2_Click(object sender, EventArgs e)
        {
            if (button2.Text == "打开串口")//为0时，表示关闭，此时可以进行打开操作
            {
                try
                {
                    serialPort1.PortName = comboBox1.Text;//获取端口号
                    serialPort1.BaudRate = Convert.ToInt32(comboBox2.Text);//设置波特率
                    //serialPort1.Parity = Parity.None;
                    //serialPort1.DataBits = 8;
                    //serialPort1.StopBits = StopBits.One;
                    serialPort1.Open();//打开串口
                    

                    button2.Text = " 关闭串口";
                }
                catch
                {
                    MessageBox.Show("串口打开错误");
                }
            }
            else  //为1时，表示开启，此时可以进行关闭操作
            {
                try
                {
                    serialPort1.Close();//关闭串口
                    button2.Text = "打开串口";//置位为0，表示状态为关闭
                }
                catch { }
            }
        }
        /// <summary>
        /// /清空显示部分
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button3_Click(object sender, EventArgs e)
        {
            textBox1.Clear();
        }
    }
}