ID 生成器

    using System;
    using System.Diagnostics;
    using System.Net;
    using System.Net.Sockets;
    using System.Threading;

    /// <summary>
    ///     ID 生成器
    /// </summary>
    public class IDFactory
    {
        #region Static Fields

        /// <summary>
        /// The factory.
        /// </summary>
        private static IDFactory factory;

        #endregion

        #region Fields

        /// <summary>
        ///     The init millisecond.
        /// </summary>
        private readonly ulong InitMillisecond;

        /// <summary>
        ///     The m watch.
        /// </summary>
        private readonly Stopwatch mWatch = new Stopwatch();

        /// <summary>
        ///     The m current millisecond.
        /// </summary>
        private ulong mCurrentMillisecond;

        /// <summary>
        ///     The m seed.
        /// </summary>
        private byte mSeed;

        #endregion

        #region Constructors and Destructors

        /// <summary>
        ///     Initializes a new instance of the <see cref="IDFactory" /> class.
        /// </summary>
        public IDFactory()
        {
            this.InitMillisecond = (ulong)(DateTime.Now - DateTime.Parse("2015-1-1")).TotalMilliseconds;
            this.mWatch.Restart();
        }

        static IDFactory()
        {
            LoadIPGroup();
        }

        #endregion

        #region Public Properties

        /// <summary>
        ///     Gets or sets the group.
        /// </summary>
        public static byte Group { get; set; }

        #endregion

        #region Public Methods and Operators

        /// <summary>
        ///     生成 ID 種子
        /// </summary>
        /// <returns>返回ID種子。參見<see cref="long" /></returns>
        public static long Create()
        {
            if (factory == null)
            {
                factory = new IDFactory();
            }

            return (long)factory.Next();
        }

        /// <summary>
        ///     獲取IP
        /// </summary>
        public static void LoadIPGroup()
        {
            string hostName = Dns.GetHostName();
            IPAddress[] addressList = Dns.GetHostAddresses(hostName);
            foreach (IPAddress ip in addressList)
            {
                if (ip.AddressFamily == AddressFamily.InterNetwork)
                {

                    byte[] data = ip.GetAddressBytes();
                    uint value = BitConverter.ToUInt32(data, 0);
                    value = value << 16;
                    value = value >> 16;
                    Group = (byte)value;
                    break;
                }
            }
        }

        /// <summary>
        ///     生成ID種子
        /// </summary>
        /// <returns>
        ///     The <see cref="ulong" />.
        /// </returns>
        public ulong Next()
        {
            ulong result = 0;
            var slock = new SpinLock();
            bool gotLock = false;
            try
            {
                while (!gotLock)
                {
                    slock.Enter(ref gotLock);
                    if (gotLock)
                    {
                        ulong cms = (ulong)this.mWatch.Elapsed.TotalMilliseconds + this.InitMillisecond;
                        if (cms != this.mCurrentMillisecond)
                        {
                            this.mSeed = 0;
                            this.mCurrentMillisecond = cms;
                        }

                        //result = ((ulong)this.Group << 58) | (this.mCurrentMillisecond << 8) | this.mSeed;
                        //result = ((ulong)Group << 9) | (this.mCurrentMillisecond << 17) | this.mSeed;
                        //result = this.mCurrentMillisecond * 1000000 + (ulong)Group * 1000 + this.mSeed;
                        result = this.mCurrentMillisecond * 10000 + (ulong)Group * 10 + this.mSeed;
                        this.mSeed++;
                    }
                }
            }
            finally
            {
                if (gotLock)
                {
                    slock.Exit();
                }
            }

            return result;
        }

        #endregion
    }