帮我写一个完整的：使用C#给产品发UDP广播，读取产品的回复

当然，我可以为您编写一个简单的C#程序，它使用UdpClient类来向指定的UDP IP地址和端口发送广播，并接收可能的响应。这里是一个基础示例：

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

class UdpBroadcastExample
{
    private const string BroadcastAddress = "255.255.255.255"; // 广播地址
    private const int BroadcastPort = 12345; // 指定端口

    static void Main(string[] args)
    {
        // 创建 UDP 客户端
        UdpClient client = new UdpClient(BroadcastPort);

        try
        {
            // 发送广播消息
            byte[] data = Encoding.ASCII.GetBytes("Hello, Product! This is a broadcast message.");
            IPEndPoint groupEP = new IPEndPoint(IPAddress.Parse(BroadcastAddress), BroadcastPort);
            client.SetSocketOption(SocketOptionLevel.Dgram, SocketOptionName.Broadcast, true);
            client.Send(data, data.Length, groupEP);

            Console.WriteLine("Broadcasted message to {0}:{1}", BroadcastAddress, BroadcastPort);

            // 接收并打印回复
            while (true)
            {
                IPEndPoint remoteEP = client.Receive(ref data);
                Console.WriteLine("Received reply from {0}:\n{1}", remoteEP.Address.ToString(), Encoding.ASCII.GetString(data));
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine("Error: " + ex.Message);
        }

        finally
        {
            // 关闭连接
            client.Close();
        }
    }
}

在这个例子中，我们创建了一个`UdpClient`，设置广播选项，然后发送一条广播消息。程序会进入无限循环等待接收来自其他设备的回应。