简单的udp消息收发

本例内容为书上1.4.4内容的改版，主要实现服务端和客户端分离。

服务端程序：

 1  static void Main(string[] args)
 2         {
 3             int dataLength;
 4             string tmpStr;
 5             byte[] dataBytes1 = new byte[1024];
 6             //指定监听端口开始
 7             Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
 8             IPEndPoint myHost = new IPEndPoint(IPAddress.Any, 8080);
 9             //指定监听端口结束
10             EndPoint client1 = new IPEndPoint(IPAddress.Any, 8080); 
11             socket.Bind(myHost);
12             while (true)
13             {
14                 Console.WriteLine("等待接收...");
15                 dataLength = socket.ReceiveFrom(dataBytes1,ref client1);
16                 tmpStr = System.Text.Encoding.Unicode.GetString(dataBytes1, 0, dataLength);
17                 Console.WriteLine($"接收到来自{client1.ToString()}的信息：{tmpStr}");
18                 if (tmpStr == "ServerOver") break;
19             }
20             socket.Close();
21             Console.WriteLine("对方已要求服务器退出，请按回车键结束。");
22             Console.ReadLine();
23         }

客户端程序：

 1 static void Main(string[] args)
 2         {
 3             byte[] dataBytes;
 4             Socket socket =new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
 5             //指定使用哪个套接字发送开始
 6             IPEndPoint myHost = new IPEndPoint(IPAddress.Any, 8081);
 7             socket.Bind(myHost);
 8             //指定使用哪个套接字发送结束
 9             //指定服务器开始
10             IPEndPoint remoteIPEnd = new IPEndPoint(IPAddress.Parse("192.168.1.105"), 8080);
11             EndPoint remoteHost = (EndPoint)remoteIPEnd;
12             //指定服务器结束
13             Console.Write("输入发送的信息：");
14             string tmpStr = Console.ReadLine();
15             dataBytes = System.Text.Encoding.Unicode.GetBytes(tmpStr);
16             socket.SendTo(dataBytes, dataBytes.Length, SocketFlags.None, remoteHost);
17             while (true)
18             {
19                 if (tmpStr == "exit")
20                 {
21                     break;
22                 }
23                 Console.Write("输入发送信息（exit退出）：");
24                 tmpStr = Console.ReadLine();
25                 dataBytes = System.Text.Encoding.Unicode.GetBytes(tmpStr);
26                 socket.SendTo(dataBytes, remoteHost);
27             }
28             socket.Close();
29             Console.WriteLine("对方已经退出了，请按回车键结束。");
30             Console.ReadLine();
31         }