C#与NTP服务端时间同步（客户端与服务端时间同步问题）

原因

很多种业务需求，要客户端与服务端的时间同步，比如在交易状态，需要验证客户端与服务端的时间，比如集群，比如记录文件安全 、审查和监控，文件时间戳，存取安全与确认等等，总之用处多多

NTP时间服务器

NTP时间服务器:Network Time Protocol
作用：用来给其他主机提供时间同步服务，在搭建服务器集群的时候，需要保证在各个节点时间一致。

上客户端代码

public void getWebTime() {

            try
            {
                // NTP服务端地址
                const string ntpServer = "192.168.100.10";

                // NTP message size - 16 bytes of the digest (RFC 2030)
                byte[] 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)
                
                IPAddress ip = IPAddress.Parse(ntpServer);

                // The UDP port number assigned to NTP is 123
                IPEndPoint ipEndPoint = new IPEndPoint(ip, 123);//addresses[0]

                // NTP uses UDP
                Socket 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 = swapEndian(intPart);
                fractPart = swapEndian(fractPart);
                ulong milliseconds = (intPart * 1000) + ((fractPart * 1000) / 0x100000000UL);

                // UTC time
                DateTime webTime = (new DateTime(1900, 1, 1, 0, 0, 0, DateTimeKind.Utc)).AddMilliseconds(milliseconds);
                string localTime = DateTime.Now.ToString("yyyyMMddHHmmss");
                // Local time
                DateTime dt = webTime.ToLocalTime();
                SyncTime(dt);

            }
            catch (Exception ex)
            {
                AppLog.Info(LoggerEnum.LogType.OTHER.ToString(), "同步时间失败 " + ex.Message);
            }
        
       
    }
    // 小端存储与大端存储的转换
    private uint swapEndian(ulong x)
    {
        return (uint)(((x & 0x000000ff) << 24) +
        ((x & 0x0000ff00) << 8) +
        ((x & 0x00ff0000) >> 8) +
        ((x & 0xff000000) >> 24));
    }
    /// 
 
    /// 设置系统时间 
    /// 
 
    public static Boolean SyncTime(DateTime currentTime)
    {
        Boolean flag = false;
        try
        {
            SystemTime sysTime = new SystemTime();
            sysTime.wYear = Convert.ToUInt16(currentTime.Year);
            sysTime.wMonth = Convert.ToUInt16(currentTime.Month);
            sysTime.wDay = Convert.ToUInt16(currentTime.Day);
            sysTime.wDayOfWeek = Convert.ToUInt16(currentTime.DayOfWeek);
            sysTime.wMinute = Convert.ToUInt16(currentTime.Minute);
            sysTime.wSecond = Convert.ToUInt16(currentTime.Second);
            sysTime.wMiliseconds = Convert.ToUInt16(currentTime.Millisecond);
            sysTime.wHour = Convert.ToUInt16(currentTime.Hour);

            SetLocalTime(ref sysTime);//设置本机时间
            flag = true;
        }
        catch (Exception)
        {
            flag = false;
        }
        return flag;
    }

用的是vs2016 是不是感觉编译老是改不了本地的时间—呵呵

对了，最后设置完，这个√ 要去掉