本文实例讲述了C#基于UDP进行异步通信的方法。分享给大家供大家参考。具体如下：

服务器端：

using System;using System.Collections.Generic;using System.Text;using System.Net;using System.Net.Sockets;using System.Threading;namespace AsyncServer{ public class UdpState { public UdpClient udpClient; public IPEndPoint ipEndPoint; public const int BufferSize = 1024; public byte[] buffer = new byte[BufferSize]; public int counter = 0; } public class AsyncUdpSever { private IPEndPoint ipEndPoint = null; private IPEndPoint remoteEP = null; private UdpClient udpReceive = null; private UdpClient udpSend = null; private const int listenPort = 1100; private const int remotePort = 1101; UdpState udpReceiveState = null; UdpState udpSendState = null; private ManualResetEvent sendDone = new ManualResetEvent(false); private ManualResetEvent receiveDone = new ManualResetEvent(false); public AsyncUdpSever() { ipEndPoint = new IPEndPoint(IPAddress.Any, listenPort); remoteEP = new IPEndPoint(Dns.GetHostAddresses(Dns.GetHostName())[0], remotePort); udpReceive = new UdpClient(ipEndPoint); udpSend = new UdpClient(); udpReceiveState = new UdpState(); udpReceiveState.udpClient = udpReceive; udpReceiveState.ipEndPoint = ipEndPoint; udpSendState = new UdpState(); udpSendState.udpClient = udpSend; udpSendState.ipEndPoint = remoteEP; } public void ReceiveMsg() { Console.WriteLine("listening for messages"); while(true) { lock (this) { IAsyncResult iar = udpReceive.BeginReceive(new AsyncCallback(ReceiveCallback), udpReceiveState); receiveDone.WaitOne(); Thread.Sleep(100); } } } private void ReceiveCallback(IAsyncResult iar) { UdpState udpReceiveState = iar.AsyncState as UdpState; if (iar.IsCompleted) { Byte[] receiveBytes = udpReceiveState.udpClient.EndReceive(iar, ref udpReceiveState.ipEndPoint); string receiveString = Encoding.ASCII.GetString(receiveBytes); Console.WriteLine("Received: {0}", receiveString); //Thread.Sleep(100); receiveDone.Set(); SendMsg(); } } private void SendMsg() { udpSend.Connect(udpSendState.ipEndPoint); udpSendState.udpClient = udpSend; udpSendState.counter ++; string message = string.Format("第{0}个UDP请求处理完成！",udpSendState.counter); Byte[] sendBytes = Encoding.Unicode.GetBytes(message); udpSend.BeginSend(sendBytes, sendBytes.Length, new AsyncCallback(SendCallback), udpSendState); sendDone.WaitOne(); } private void SendCallback(IAsyncResult iar) { UdpState udpState = iar.AsyncState as UdpState; Console.WriteLine("第{0}个请求处理完毕！", udpState.counter); Console.WriteLine("number of bytes sent: {0}", udpState.udpClient.EndSend(iar)); sendDone.Set(); } public static void Main() { AsyncUdpSever aus = new AsyncUdpSever(); Thread t = new Thread(new ThreadStart(aus.ReceiveMsg)); t.Start(); Console.Read(); } }}

客户端：

using System;using System.Collections.Generic;using System.Text;using System.Net;using System.Net.Sockets;using System.Threading;namespace AsyncClient{ public class UdpState { public UdpClient udpClient = null; public IPEndPoint ipEndPoint = null; public const int BufferSize = 1024; public byte[] buffer = new byte[BufferSize]; public int counter = 0; } public class AsyncUdpClient { public static bool messageSent = false; // Receive a message and write it to the console. private const int listenPort = 1101; private const int remotePort = 1100; private IPEndPoint localEP = null; private IPEndPoint remoteEP = null; private UdpClient udpReceive = null; private UdpClient udpSend = null; private UdpState udpSendState = null; private UdpState udpReceiveState = null; private int counter = 0; private ManualResetEvent sendDone = new ManualResetEvent(false); private ManualResetEvent receiveDone = new ManualResetEvent(false); private Socket receiveSocket; private Socket sendSocket; public AsyncUdpClient() { localEP = new IPEndPoint(IPAddress.Any, listenPort); remoteEP = new IPEndPoint(Dns.GetHostAddresses(Dns.GetHostName())[0],remotePort); udpReceive = new UdpClient(localEP); udpSend = new UdpClient(); udpSendState = new UdpState(); udpSendState.ipEndPoint = remoteEP; udpSendState.udpClient = udpSend; udpReceiveState = new UdpState(); udpReceiveState.ipEndPoint = remoteEP; udpReceiveState.udpClient = udpReceive; receiveSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp); receiveSocket.Bind(localEP); sendSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp); sendSocket.Bind(remoteEP); } public void SendMsg() { udpSend.Connect(remoteEP); //Thread t = new Thread(new ThreadStart(ReceiveMessages)); //t.Start(); Byte[] sendBytes; string message; while (true) { message = "Client" + (counter++).ToString(); lock (this) { sendBytes = Encoding.ASCII.GetBytes(message); udpSendState.counter = counter; udpSend.BeginSend(sendBytes, sendBytes.Length, new AsyncCallback(SendCallback), udpSendState); sendDone.WaitOne(); Thread.Sleep(200); ReceiveMessages(); } } } public void SendCallback(IAsyncResult iar) { UdpState udpState = iar.AsyncState as UdpState; if (iar.IsCompleted) { Console.WriteLine("第{0}个发送完毕！", udpState.counter); Console.WriteLine("number of bytes sent: {0}", udpState.udpClient.EndSend(iar)); //if (udpState.counter == 10) //{ // udpState.udpClient.Close(); //} sendDone.Set(); } } public void ReceiveMessages() { lock (this) { udpReceive.BeginReceive(new AsyncCallback(ReceiveCallback), udpReceiveState); receiveDone.WaitOne(); Thread.Sleep(100); } } public void ReceiveCallback(IAsyncResult iar) { UdpState udpState = iar.AsyncState as UdpState; if (iar.IsCompleted) { Byte[] receiveBytes = udpState.udpClient.EndReceive(iar, ref udpReceiveState.ipEndPoint); string receiveString = Encoding.Unicode.GetString(receiveBytes); Console.WriteLine("Received: {0}", receiveString); receiveDone.Set(); } } public static void Main() { AsyncUdpClient auc = new AsyncUdpClient(); auc.SendMsg(); Console.Read(); } }}

希望本文所述对大家的C#程序设计有所帮助。