1. 服务端

    internal class Program{static void Main(string[] args){//1.创建SocketSocket socketServer =new Socket(AddressFamily.InterNetwork,SocketType.Dgram,ProtocolType.Udp);//2.绑定IP、端口号EndPoint endPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 5566);socketServer.Bind(endPoint);//3.接收消息byte[] buffer = new byte[1024];EndPoint remoteEP = new IPEndPoint(IPAddress.Any, 0);int length = socketServer.ReceiveFrom(buffer, ref remoteEP);Console.WriteLine(Encoding.UTF8.GetString(buffer, 0, length));socketServer.Close();Console.ReadLine();}}

2.客户端

internal class Program
{static void Main(string[] args){// 创建SocketSocket socketClient = new Socket(AddressFamily.InterNetwork, SocketType.Dgram,             ProtocolType.Udp);// 目标IP和端口号EndPoint endPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 5566);// 发送消息string message = "Hello, Server!";byte[] buffer = Encoding.UTF8.GetBytes(message);socketClient.SendTo(buffer, endPoint);Console.WriteLine("消息已发送");socketClient.Close();Console.ReadLine();}
}

3.执行

先启动服务端exe，再启动客户端exe，客户端会向服务端发送消息。