UDP异步通信C#

C# 编写的简单UDP异步通信程序（控制台）

客户端发送请求，服务器端响应机制

1. [代码]UDP客户端代码    

01using System;

02using System.Text;

03using System.Net;

04using System.Net.Sockets;

05 

06namespace Client

07{

08    classProgram

09    {

10        //客户端 Socket对象

11        privatestatic Socket clientSocket;

12        //服务器端 终点

13        privatestatic EndPoint epServer;

14        //接收数据的字符数组

15        privatestatic byte[] receiveData;

16 

17        publicstatic void Main(string[] args)

18        {

19            //客户端Socket对象实例化

20            clientSocket =new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

21            //设置服务器端IP地址和对应端口

22            IPEndPoint server =new IPEndPoint(IPAddress.Parse("192.168.1.165"), 11000);

23            //实例化服务器端 终点

24            epServer = (EndPoint)server;

25            stringmsg;     //要发送的消息

26            byte[] sendData;   //要发送的字符串

27            while(true) {

28                msg = Console.ReadLine();  //输入要发送的消息

29                if(msg == "exit")break;   //当输入“exit”时，退出客户端程序

30                //将消息通过ASCII编码转换为字符数组，

31                //如果要发送汉字或其他特殊符号，可以采用UTF-8

32                sendData = Encoding.ASCII.GetBytes(msg);   

33                //开始异步发送消息

34                //参数：sendData           要发送的数据

35                //参数：0：                 要发送数据的起始位置

36                //参数：sendData.Length：   要发送数据的字节数

37                //参数：SocketFlags.None：  按位组合方式

38                //参数：epServer：          接收方设备（包含IP和端口）

39                //参数：new AsyncCallback(SendData):   委托

40                //参数：null：          请求的状态信息

41                clientSocket.BeginSendTo(sendData, 0, sendData.Length, SocketFlags.None,

42                    epServer,new AsyncCallback(SendData),null);

43                //实例化接收数据的字符数组

44                //若在声明时已经初始化，此处依然要进行重新初始化

45                //当上次接收的数据长度大于本次，则该数组里包含上次接收的残留数据

46                //比如：上次接收“你个小逗逼”。本次接收“开玩笑”。

47                //则数组中的数据为：“开玩笑逗逼”。

48                receiveData =new byte[1024];

49                //开始异步接收消息

50                //参数部分与异步发送部分对应，基本一致

51                clientSocket.BeginReceiveFrom(receiveData, 0, receiveData.Length, SocketFlags.None,

52                    refepServer, new AsyncCallback(ReceiveData), null);

53            }

54        }

55 

56        //异步发送消息的委托函数

57        privatestatic void SendData(IAsyncResult iar)

58        {

59            //完成异步发送

60            clientSocket.EndSend(iar);

61        }

62 

63        //异步接收消息的委托函数

64        privatestatic void ReceiveData(IAsyncResult iar)

65        {

66            //完成异步接收  recv 表示接收到的字节数

67            intrecv = clientSocket.EndReceive(iar);

68            //将接收到的数据打印出来

69            Console.WriteLine("Server: "+ Encoding.ASCII.GetString(receiveData, 0, recv));

70        }

71 

72    }

73}

2. [代码]UDP服务器端代码    

01using System;

02using System.Text;

03using System.Net;

04using System.Net.Sockets;

05 

06namespace Server

07{

08    classAsyncUdpServer

09    {

10        //服务器端Socket对象

11        privatestatic Socket serverSocket;

12        //接收数据的字符数组

13        privatestatic byte[] receiveData =new byte[1024];

14         

15        publicstatic void Main(string[] args)

16        {

17            //实例化服务器端Socket对象

18            serverSocket =new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

19            //服务器端的IP和端口，IPAddress.Any实际是：0.0.0.0，表示任意，基本上表示本机IP

20            IPEndPoint server =new IPEndPoint(IPAddress.Any, 11000);

21            //Socket对象跟服务器端的IP和端口绑定

22            serverSocket.Bind(server);

23            //客户端的IP和端口，端口 0 表示任意端口

24            IPEndPoint clients =new IPEndPoint(IPAddress.Any, 0);

25            //实例化客户端 终点

26            EndPoint epSender = (EndPoint)clients;

27            //开始异步接收消息  接收后，epSender存储的是发送方的IP和端口

28            serverSocket.BeginReceiveFrom(receiveData, 0, receiveData.Length, SocketFlags.None,

29                refepSender, new AsyncCallback(ReceiveData), epSender);

30            Console.WriteLine("Listening...");

31            Console.ReadLine();

32        }

33 

34        privatestatic void SendData(IAsyncResult iar)

35        {

36            serverSocket.EndSend(iar);

37        }

38 

39        privatestatic void ReceiveData(IAsyncResult iar)

40        {

41            //客户端的IP和端口，端口 0 表示任意端口

42            IPEndPoint client =new IPEndPoint(IPAddress.Any, 0);

43            //实例化客户端 终点

44            EndPoint epSender = (EndPoint)client;

45            //结束异步接收消息  recv 表示接收到的字符数

46            intrecv = serverSocket.EndReceiveFrom(iar, refepSender);           

47            //将接收到的数据打印出来，发送方采用什么编码方式，此处就采用什么编码方式 转换成字符串

48            Console.WriteLine("Client:"+ Encoding.ASCII.GetString(receiveData, 0, recv));

49            //定义要发送回客户端的消息，采用ASCII编码，

50            //如果要发送汉字或其他特殊符号，可以采用UTF-8           

51            byte[] sendData = Encoding.ASCII.GetBytes("hello");

52            //开始异步发送消息  epSender是上次接收消息时的客户端IP和端口信息

53            serverSocket.BeginSendTo(sendData, 0, sendData.Length, SocketFlags.None,

54                epSender,new AsyncCallback(SendData), epSender);

55            //重新实例化接收数据字节数组

56            receiveData =new byte[1024];

57            //开始异步接收消息，此处的委托函数是这个函数本身，递归

58            serverSocket.BeginReceiveFrom(receiveData, 0, receiveData.Length, SocketFlags.None,

59                refepSender, new AsyncCallback(ReceiveData), epSender);

60        }

61 

62    }

63}