注意事项

1. 需要将 Unity API改成 .Net Framework 其他的不支持

using System;
using System.IO.Ports;
using System.Text;
using System.Threading;
using UnityEngine;

public class MainController : MonoBehaviour
{
    public string portName;
    public int baudRate;
    public Parity parity;
    public int dataBits;
    public StopBits stopBits;
    
    private SerialPort _serialPort;
    private Thread _thread;
    private void Start()
    {
        _serialPort = new SerialPort(portName, baudRate, parity, dataBits, stopBits);
        _serialPort.Open();
        _thread = new Thread(new ThreadStart(DataReceived));
        _thread.Start();
    }
    
    private void DataReceived()
    {
        while (true)
        {
            if (_serialPort.IsOpen)
            {
                int count = _serialPort.BytesToRead;
                if (count > 0)
                {
                    byte[] readBuffer = new byte[count];
                    try
                    {
                        _serialPort.Read(readBuffer, 0, count);
                        print(Encoding.UTF8.GetString(readBuffer));
                        // DataProcessing(readBuffer);//数据处理
                    }
                    catch (Exception ex)
                    {
                        Debug.Log(ex.Message);
                    }
                }
            }
            Thread.Sleep(10);
        }
    }
    
    public void DataProcessing(byte[] data)
    {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < data.Length; i++)
        {
            sb.AppendFormat("{0:x2}" + "", data[i]);
        }
        Debug.Log(sb.ToString());
    }
    private void Update() 
    {
        if (Input.GetKeyDown(KeyCode.Space))
        {
            byte[] buffer = Encoding.UTF8.GetBytes("你好啊");
            _serialPort.Write(  buffer, 0, buffer.Length);
        }

    
    }

    private void OnDestroy()
    {
        if (_serialPort != null && _serialPort.IsOpen)
        {
            _serialPort.Close();
            print("已经关闭");
        }
        if (_thread != null && _thread.IsAlive)
        {
            print("线程关闭");
            _thread.Abort(); // 也可以使用其他方法关闭线程，例如设置标志来结束线程循环
        }
    }
}