Udp分包过程（C#）

来源：互联网发布：武汉理工大网络编辑：程序博客网时间：2024/05/18 21:43

Send与SendTo以及Receive与Receivefrom之间的区别？

一般情况下：

Send、Receive用于TCP

SendTo、Receivefrom用于UDP

Udp发送超大文件一般采用分包发送的方式

Udp分包数据量的上限： 65k

   #region 分包处理        public static ICollection<UdpPacket> Split( byte[] datagram, int chunkLength)        {                 string FILE = "First";//第一个分包的标识            string Mid= "Mid";    //后续分包  的标识            if (datagram == null)                throw new ArgumentNullException("datagram");            //存储所有的数据包            List<UdpPacket> packets = new List<UdpPacket>();            //完整的UDP数据包            int chunks = datagram.Length / chunkLength;            //最后一个不完整的数据包的数据量            int remainder = datagram.Length % chunkLength;            //判断最后一个数据包，计算总的数据包            int total = chunks;            if (remainder > 0) total++;

           //进行分包，区别对待第一个包和后续包

            //遍历所有的完整的UDP数据包                       for (int i = 1; i <= chunks; i++)                {                 byte[] chunk=new byte[chunkLength];                Buffer.BlockCopy(datagram,(i-1)*chunkLength,chunk,0,chunkLength);

                //第一个分包                if (i == 1)                {                    packets.Add(new UdpPacket(FILE,total, i, chunk, chunkLength, remainder));                }

               //后续分包标识                    else                    packets.Add(new UdpPacket(Mid, total, i, chunk, chunkLength, remainder));                }

            //最后一个分包                if (remainder > 0)                {                                                       if (total != 1)                    {                        int length = datagram.Length - (chunkLength * chunks);                        byte[] chunk = new byte[length];                        Buffer.BlockCopy(datagram, chunks * chunkLength, chunk, 0, length);                        packets.Add(new UdpPacket(Mid, total, total, chunk, chunkLength, remainder));                    }                    else                    {                        int length = datagram.Length - (chunkLength * chunks);                        byte[] chunk = new byte[length];                        Buffer.BlockCopy(datagram, 0, chunk, 0, length);                        packets.Add(new UdpPacket(FILE, total, total, chunk, chunkLength, remainder));                                           }                                   }                                 return packets;        }         #endregion

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