如何获取网络标准时间

我提供一种获取网络标准时间的方法

public static DateTime GetNetworkTime()
        {
            
                //default Windows time server
                const string ntpServer = "time.windows.com";


                // NTP message size - 16 bytes of the digest (RFC 2030)
                var ntpData = new byte[48];


                //Setting the Leap Indicator, Version Number and Mode values
                ntpData[0] = 0x1B; //LI = 0 (no warning), VN = 3 (IPv4 only), Mode = 3 (Client Mode)


                var addresses = Dns.GetHostEntry(ntpServer).AddressList;


                //The UDP port number assigned to NTP is 123
                var ipEndPoint = new IPEndPoint(addresses[0], 123);
                //NTP uses UDP
                var socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);


                socket.Connect(ipEndPoint);


                //Stops code hang if NTP is blocked
                socket.ReceiveTimeout = 3000;


                socket.Send(ntpData);
                socket.Receive(ntpData);
                socket.Close();


                //Offset to get to the "Transmit Timestamp" field (time at which the reply 
                //departed the server for the client, in 64-bit timestamp format."
                const byte serverReplyTime = 40;


                //Get the seconds part
                ulong intPart = BitConverter.ToUInt32(ntpData, serverReplyTime);


                //Get the seconds fraction
                ulong fractPart = BitConverter.ToUInt32(ntpData, serverReplyTime + 4);


                //Convert From big-endian to little-endian
                intPart = SwapEndianness(intPart);
                fractPart = SwapEndianness(fractPart);


                var milliseconds = (intPart * 1000) + ((fractPart * 1000) / 0x100000000L);


                //**UTC** time
                var networkDateTime = (new DateTime(1900, 1, 1, 0, 0, 0, DateTimeKind.Utc)).AddMilliseconds((long)milliseconds);


                return networkDateTime.ToLocalTime();
        }


        // stackoverflow.com/a/3294698/162671
        static uint SwapEndianness(ulong x)
        {
            return (uint)(((x & 0x000000ff) << 24) +
                           ((x & 0x0000ff00) << 8) +
                           ((x & 0x00ff0000) >> 8) +
                           ((x & 0xff000000) >> 24));


        }