C#窗体程序，创建了5个串口，先检查串口的连接状态，指定COM3接收外部十六进制数据“49 28 30 30 2C 30 30 31 2C 31 29”后就触发UDP发送事件的完整代码

在C#中，创建串口并监控其连接状态通常涉及`System.IO.Ports.SerialPort`类，以及使用`System.Net.Sockets.UdpClient`处理UDP通信。下面是一个简单的示例，展示了如何创建5个串口，检查连接，并在接收到特定数据后触发UDP发送事件：

using System;
using System.IO.Ports;
using System.Net;
using System.Net.Sockets;

class Program
{
    private SerialPort[] serialPorts = new SerialPort[5] { ... // 初始化你的5个串口实例 }
    private UdpClient udpClient;

    static void Main()
    {
        Program app = new Program();
        app.InitializeSerialPorts();
        app.StartUdp();
        Console.WriteLine("等待串口接收数据...");
        app.Run();
    }

    private void InitializeSerialPorts()
    {
        foreach (SerialPort port in serialPorts)
        {
            port.Open();
            port.DataReceived += Port_DataReceived; // 添加数据接收事件
        }
    }

    private void StartUdp()
    {
        udpClient = new UdpClient(); // UDP监听端口
        udpClient.Client.ReceiveBufferSize = 1024;
        udpClient.MessageReceived += UdpClient_MessageReceived;
    }

    private void Run()
    {
        while (true) // 这里可以添加其他UI线程的工作...
        {
            Thread.Sleep(1000); // 主循环
        }
    }

    private void Port_DataReceived(object sender, SerialDataReceivedEventArgs e)
    {
        SerialPort sp = (SerialPort)sender;
        if (sp.BytesToRead > 0 && sp.ReadByte() == '4') // 检查是否开始接收到期望的数据
        {
            string hexData = ReadHexData(sp);
            OnHexDataReceived(hexData);
        }
    }

    private void ReadHexData(SerialPort sp)
    {
        byte[] bytes = new byte[sp.In_waiting];
        sp.Read(bytes, 0, bytes.Length);
        return BitConverter.ToString(bytes).Replace("-", "");
    }

    private void UdpClient_MessageReceived(object sender, UdpReceiveEventArgs e)
    {
        OnUdpMessageReceived(e.Buffer.ToArray());
    }

    protected virtual void OnHexDataReceived(string hexData)
    {
        if (hexData == "492830302C3030312C3129") // 如果接收到预设数据
        {
            SendUdp(hexData);
        }
    }

    protected virtual void SendUdp(string data)
    {
        byte[] sendData = Encoding.ASCII.GetBytes(data);
        udpClient.Send(sendData, sendData.Length, "localhost", 8000); // 发送到本地UDP服务器
    }