帮我写个C#UDP广播收发

在C#中，你可以使用Socket类和UdpClient类来创建一个简单的UDP广播收发程序。以下是发送广播消息的示例：

using System;
using System.Net;
using System.Net.Sockets;

class UdpBroadcastSender
{
    private const int PORT = 7; // UDP广播端口
    private static IPEndPoint broadcastAddress = new IPEndPoint(IPAddress.Broadcast, PORT);

    public static void Main()
    {
        try
        {
            using (UdpClient client = new UdpClient(PORT))
            {
                string message = "Hello, UDP Broadcast!";
                byte[] data = Encoding.UTF8.GetBytes(message);
                
                client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, true);
                client.Send(data, data.Length, broadcastAddress);
                Console.WriteLine($"Sent message: {message}");
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error sending broadcast: {ex.Message}");
        }
    }
}

接收广播消息的部分则需要监听来自所有网络接口的数据：

class UdpBroadcastReceiver
{
    private const int PORT = 7;
    private UdpClient listener = new UdpClient(PORT);

    public static void Main()
    {
        try
        {
            listener.BeginReceive(ReceiveCallback, null);
            Console.WriteLine("Listening for UDP broadcasts...");
            Console.ReadKey();
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error receiving: {ex.Message}");
        }
        finally
        {
            listener.Close();
        }
    }

    private static async void ReceiveCallback(IAsyncResult result)
    {
        UdpReceiveResult received = listener.EndReceive(result);
        Console.WriteLine($"Received: {Encoding.UTF8.GetString(received.Buffer)}");
        listener.BeginReceive(ReceiveCallback, null);
    }
}