using System;using System.Net.Sockets;using System.Net;using System.Text;public class UdpClientTest{    public static void Main()    {        UdpClient udpClient = new UdpClient(6000);    //侦听本地端口        IPEndPoint host = new IPEndPoint(IPAddress.Parse("192.168.191.1"),7000);    //这里是目标主机和端口        Byte[] msg = new UTF8Encoding(true).GetBytes("Hee How are U?");        udpClient.Send(msg, msg.Length, host);                IPEndPoint remoteHost = new IPEndPoint(IPAddress.Any,0);        Byte[] receivedBytes = udpClient.Receive(ref remoteHost);        string returnData =http://www.mamicode.com/ Encoding.ASCII.GetString(receivedBytes);        Console.WriteLine("This is message you received is :"+returnData.ToString());        Console.WriteLine("This is was sent form : "+remoteHost.Address.ToString() + " port number " + remoteHost.Port.ToString());                udpClient.Close();    }}

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Windows.Forms;using System.Net;using System.Net.Sockets;namespace Test{    class UdpServer    {        public Socket serverSocket;        public byte[] dataStream;        public byte[] receivedBytes;        public EndPoint epSender;        // 关闭前一个窗口的回调函数        public delegate void OnDataReceived();        public event OnDataReceived onDataReceive;        public UdpServer()        {            this.dataStream = new byte[10240];        }        public void Open(int port)         {            this.serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);            IPEndPoint serverPoint = new IPEndPoint(IPAddress.Any, port);            this.serverSocket.Bind(serverPoint);        }                public void Close()         {            this.serverSocket.Shutdown(SocketShutdown.Both);            this.serverSocket.Close();            this.serverSocket.Shutdown(SocketShutdown.Both);            this.serverSocket.Close();           }                public void Listen()        {            try            {                IPEndPoint clientPoint = new IPEndPoint(IPAddress.Any, 0);                this.epSender = (EndPoint)clientPoint;                this.serverSocket.BeginReceiveFrom(this.dataStream, 0,                                        this.dataStream.Length,                                        SocketFlags.None,                                         ref epSender,                                         new AsyncCallback(ReceiveData),                                         epSender);            }            catch (Exception ex)            {                MessageBox.Show(ex.Message, "UDP连接创建失败", MessageBoxButtons.OK, MessageBoxIcon.Error);            }                                            }            private void ReceiveData(IAsyncResult asyncResult)        {            try            {                int recv_len = serverSocket.EndReceiveFrom(asyncResult, ref epSender);                this.serverSocket.BeginReceiveFrom(this.dataStream, 0,                                        this.dataStream.Length,                                        SocketFlags.None,                                         ref epSender,                                         new AsyncCallback(ReceiveData),                                         epSender);                                                    receivedBytes = new byte[recv_len];                Array.Copy(dataStream, 0, receivedBytes,0,recv_len);                Console.WriteLine("got "+recv_len.ToString() + " Bytes");                Console.WriteLine("str is: "+ Encoding.ASCII.GetString(dataStream,0,recv_len));                                onDataReceive();            }            catch (Exception ex)            {               MessageBox.Show(ex.Message, "UDP接收异常", MessageBoxButtons.OK, MessageBoxIcon.Warning);            }            }            /*        public void SendTo(IPEndPoint dstEndPoint, byte[] byteData,int length) {            EndPoint dstHost = (EndPoint)dstEndPoint;            // Begin sending the data to the remote device.            this.serverSocket.BeginSendTo(byteData, 0, length,                     SocketFlags.None, dstHost,            new AsyncCallback(SendCallback), this.serverSocket);        }*/             private void SendTo(IPEndPoint dstEndPoint, string text) {            byte[]    byteData =http://www.mamicode.com/ Encoding.ASCII.GetBytes(text);            EndPoint dstHost = (EndPoint)dstEndPoint;            // Begin sending the data to the remote device.            this.serverSocket.BeginSendTo(byteData, 0, byteData.Length,                     SocketFlags.None, dstHost,             new AsyncCallback(SendCallback), this.serverSocket);        }            private void SendCallback(IAsyncResult ar) {            try {                // Retrieve the socket from the state object.                Socket handler = (Socket) ar.AsyncState;                 // Complete sending the data to the remote device.                int bytesSent = handler.EndSend(ar);                Console.WriteLine("Sent {0} bytes to client.", bytesSent);                 //handler.Shutdown(SocketShutdown.Both);                //handler.Close();             } catch (Exception ex) {                MessageBox.Show(ex.Message, "UDP发送异常", MessageBoxButtons.OK, MessageBoxIcon.Warning);            }        }                public static void Main()        {            IPEndPoint dstPoint = new IPEndPoint(IPAddress.Parse("192.168.65.230"),7000);//发送到本地7000端口            UdpServer udpServer = new UdpServer();             udpServer.Open(6000);    //本地侦听6000端口            udpServer.Listen();            udpServer.SendTo(dstPoint, "Hello World!!!");                        while(true)            {                            }        }    }}