基於Socket的UDP發包程序

UDP(User Datagram Protocol,用戶數據報協議)是在互聯網中常用的傳輸層協議，該協議提供了向另一用戶程序發送的消息的最簡便的協議機制。與TCP一樣，其默認的下層協議是IP.UDP是面向操作的，不提供提交和復制保護，因此不能保證數據的可靠性傳輸。UDP一般用在可靠性較高的局域網中。

.NET 下可使用Socket 類編寫基於UDP的網絡程序，只要在創建Socket時將構造函數函數的第三個參數選為枚舉值ProtocolType.Udp即可.此外，.NET的System.Net.Sockets命名空間下還有一個UdpClient類，可專門用於UDP的網絡編程。-----摘自< C#.NET 框架高級編程技術案例教程  郭文夷等 P163>

第一種，使用Socket類

 IPEndPoint ip = new IPEndPoint(IPAddress.Parse(txtIP.Text), int.Parse(txtPort.Text));
            Socket  serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            serverSocket.Bind(ip);

第二種，使用UdpClient類

 IPAddress address = IPAddress.Parse(txtLocalIp.Text);
            int port = Int32.Parse(txtLocalPort.Text);
            IPEndPoint endPoint = new IPEndPoint(address, port);
            UdpClient udpClient = new UdpClient(endPoint);

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本文主要采用第一種，基於Socket編寫一個Udp發包程序。服務器端不斷發包，客戶端根據接收到的點數據在窗體上繪制點，效果如下所示：

 

一.服務器端

1.創建一個Socket對象，綁定服務器端Ip和端口號。

2.創建一個線程用戶獲取客戶機的Ip和端口號。大致是這樣的，客戶機連接到服務器，同時發送一個"你好"的消息，服務器端這樣就可以獲取到客戶機的Ip和端口。

  private void btnStart_Click(object sender, EventArgs e)
        {
            if (serverSocket != null)
            {
                return;
            }
            IPEndPoint ip = new IPEndPoint(IPAddress.Parse(txtIP.Text), int.Parse(txtPort.Text));
            serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            serverSocket.Bind(ip);

            AppendTextToTxtLog(string.Format("服務器端是{0},正在等待客戶端的連接",ip.ToString()));
            Thread thread = new Thread(ReceiveData);
            thread.IsBackground = true;
            thread.Start();

        }

3.發送數據

 private void SendData()
        {
            byte[] data = new byte[1024 * 1024];
            int j = 1000;
            Random r = new Random(100);
            while (j >0)
            {
                j--;
                int x = r.Next(500);
                int y = r.Next(500);
                string msg = x.ToString() +","+ y.ToString();
                data = Encoding.Default.GetBytes(msg);
                for (int k = 0; k < RemoteList.Count; k++)
                {
                    int i = serverSocket.SendTo(data, data.Length, SocketFlags.None,RemoteList[k]);
                    AppendTextToTxtLog(string.Format("發送給客戶端{0}的消息是{1}", RemoteList[k].ToString(), msg));
                }
            }
        }

客戶端

1.連接到服務器端

   private void btnConnected_Click(object sender, EventArgs e)
        {
            byte[] data = new byte[1024];

            IPEndPoint ip = new IPEndPoint(IPAddress.Parse("192.168.10.179"), 50000);
            ServerSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
            string welcome = "你好!";
            data = Encoding.Default.GetBytes(welcome);
            ServerSocket.SendTo(data, data.Length, SocketFlags.None, ip);
            Thread thread = new Thread(ReceiveData);
            thread.IsBackground = true;
            thread.Start();
        }

2.接受數據

 /// <summary>
        /// 接受消息
        /// </summary>
        private void ReceiveData()
        {
            byte[] data = new byte[1024];
            IPEndPoint endPoint = new IPEndPoint(IPAddress.Any, 0);
            EndPoint remote = (EndPoint)endPoint;
            while (true)
            {
                int len = 0;
                try
                {
                   len = ServerSocket.ReceiveFrom(data, ref remote);
                   string str = Encoding.Default.GetString(data, 0, len);
                   string[] points = str.Split(',');
                   int x = int.Parse(points[0]);
                   int y = int.Parse(points[1]);
                   Point p = new Point(x, y);
                   Thread thread = new Thread(new ParameterizedThreadStart(drawPoint));
                   thread.IsBackground = true;
                   thread.Start(p);
                }
                catch (Exception  ex)
                {
                    
                   
                }
            }
        
        }

 3.繪制

/// <summary>
        /// 繪制
        /// </summary>
        /// <param name="p"></param>
        public void drawPoint(object p)
        {

            Point point = (Point)p;
            Graphics g = this.panel1.CreateGraphics();
            Pen pen = new Pen(Color.Black);
            g.DrawEllipse(pen, point.X, point.Y, 5, 5);
        }

源碼下載: http://download.csdn.net/detail/gongchao1212/9591239