Socket通讯之UDP

发送消息的类：

/// <summary>
    /// 发送消息
    /// </summary>
    public class UdpSendMessage
    {
        System.Net.Sockets.UdpClient udpClient = null;
        public static int BufferSize = 1024;

        public UdpSendMessage()
        {
            udpClient = new System.Net.Sockets.UdpClient();
        }

        /// <summary>
        /// 发送Socket消息
        /// </summary>
        /// <param name="ip">远程IP</param>
        /// <param name="port">远程端口号</param>
        /// <param name="datagram">数据包</param>
        private void Send(string ip, int port, byte[] datagram)
        {
            //
            System.Net.IPEndPoint endPoint = new System.Net.IPEndPoint(System.Net.IPAddress.Parse(ip), port);
            if (datagram.Length > BufferSize)
            {
                for (int i = 0, srcOffset = 0; i < datagram.Length / BufferSize + 1; i++, srcOffset++)
                {
                    if (i == datagram.Length / BufferSize)
                    {
                        byte[] dst = new byte[datagram.Length - BufferSize * i];
                        Buffer.BlockCopy(datagram, srcOffset * BufferSize, dst, 0, datagram.Length - BufferSize * i);
                        udpClient.BeginSend(dst, dst.Length, endPoint, new AsyncCallback(SendCallback), true);
                    }
                    else
                    {
                        byte[] dst = new byte[BufferSize];
                        Buffer.BlockCopy(datagram, srcOffset * BufferSize, dst, 0, BufferSize);
                        udpClient.BeginSend(dst, dst.Length, endPoint, new AsyncCallback(SendCallback), false);
                    }
                    System.Threading.Thread.Sleep(1);
                }
            }
            else
            {
                udpClient.BeginSend(datagram, datagram.Length, endPoint, new AsyncCallback(SendCallback), true);
            }
        }

        private void SendCallback(IAsyncResult asynResult)
        {
            try
            {
                if ((bool)asynResult.AsyncState)
                {
                    udpClient.EndSend(asynResult);
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
    }

　　接收消息的类

 /// <summary>
    /// 接收消息
    /// </summary>
    public class UdpResiveMessage
    {
        System.Net.Sockets.UdpClient udpClient = null;
        StringBuilder sbResvieMsg = new StringBuilder();

        /// <summary>
        /// 打开监听端
        /// </summary>
        /// <param name="port">监听端口号</param>
        public void BeginListen(int port)
        {
            udpClient = new System.Net.Sockets.UdpClient(port, System.Net.Sockets.AddressFamily.InterNetwork);
            udpClient.BeginReceive(new AsyncCallback(ReceiveCallback), null);
        }

        private void ReceiveCallback(IAsyncResult asynResult)
        {
            try
            {
                IPEndPoint remoteEP = new IPEndPoint(IPAddress.Any, 0);
                byte[] buffer = udpClient.EndReceive(asynResult, ref remoteEP);
                string ss = System.Text.Encoding.Default.GetString(buffer);
                if (!string.IsNullOrWhiteSpace(ss))
                {
                    sbResvieMsg.Append(ss);
                }
                if (buffer.Length < 1024)
                {
                    MessageBox.Show(sbResvieMsg.ToString());
                }
                udpClient.BeginReceive(new AsyncCallback(ReceiveCallback), null);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
    }

　　测试代码：打开监听端：

UdpResiveMessage udpListen = new UdpResiveMessage();
udpListen.BeginListen(10003);

　　发送字符串

UdpSendMessage udpSend = new UdpSendMessage();
            udpSend.Send("127.0.0.1", 10003, System.Text.Encoding.Default.GetBytes(this.textBox1.Text.Trim()));

　　发送文件

 /// <summary>
        /// 将文件转换为字节流
        /// </summary>
        /// <param name="sFilePath"></param>
        /// <returns></returns>
        public byte[] GetFileByte(string sFilePath)
        {
            try
            {
                if (!System.IO.File.Exists(sFilePath))
                {
                    return null;
                }
                else
                {
                    FileStream fs = new FileStream(sFilePath, FileMode.Open, FileAccess.Read);
                    byte[] buffur = new byte[fs.Length];
                    fs.Read(buffur, 0, (int)fs.Length);
                    fs.Close();
                    return buffur;
                }
            }
            catch //(Exception ex)
            {
                return null;
            }
        }

        /// <summary>
        /// 发送文件
        /// </summary>
        private void SendFile()
        {
            UdpSendMessage udpSend = new UdpSendMessage();
            udpSend.Send("127.0.0.1", 10003, GetFileByte("d:\\BookOrder.pdf"));
        }