參考地址：https://blog.csdn.net/w200221626/article/details/52064976

 /// <summary>
    /// 動態生產有規律的ID
    /// </summary>
    public class Snowflake
    {
        private static long machineId;//機器ID
        private static long datacenterId = 0L;//資料ID
        private static long sequence = 0L;//計數從零開始
 


        private static long twepoch = 687888001020L; //唯一時間隨機量

        private static long machineIdBits = 5L; //機器碼位元組數
        private static long datacenterIdBits = 5L;//資料位元組數
        public static long maxMachineId = -1L ^ -1L << (int)machineIdBits; //最大機器ID
        private static long maxDatacenterId = -1L
 
 ^ (-1L << (int)datacenterIdBits);//最大資料ID

        private static long sequenceBits = 12L; //計數器位元組數，12個位元組用來儲存計數碼        
        private static long machineIdShift = sequenceBits; //機器碼資料左移位數，就是後面計數器佔用的位數
        private static long datacenterIdShift = sequenceBits + machineIdBits;
        private
 
 static long timestampLeftShift = sequenceBits + machineIdBits + datacenterIdBits; //時間戳左移動位數就是機器碼+計數器總位元組數+資料位元組數
        public static long sequenceMask = -1L ^ -1L << (int)sequenceBits; //一微秒內可以產生計數，如果達到該值則等到下一微妙在進行生成
        private static long lastTimestamp = -1L;//最後時間戳

        private static object syncRoot = new object();//加鎖物件
        static Snowflake snowflake;

        public static Snowflake Instance()
        {
            if (snowflake == null)
                snowflake = new Snowflake();
            return snowflake;
        }

        public Snowflake()
        {
            Snowflakes(0L, -1);
        }

        public Snowflake(long machineId)
        {
            Snowflakes(machineId, -1);
        }

        public Snowflake(long machineId, long datacenterId)
        {
            Snowflakes(machineId, datacenterId);
        }

        private void Snowflakes(long machineId, long datacenterId)
        {
            if (machineId >= 0)
            {
                if (machineId > maxMachineId)
                {
                    throw new Exception("機器碼ID非法");
                }
                Snowflake.machineId = machineId;
            }
            if (datacenterId >= 0)
            {
                if (datacenterId > maxDatacenterId)
                {
                    throw new Exception("資料中心ID非法");
                }
                Snowflake.datacenterId = datacenterId;
            }
        }

        /// <summary>
        /// 生成當前時間戳
        /// </summary>
        /// <returns>毫秒</returns>
        private static long GetTimestamp()
        {
            return (long)(DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).TotalMilliseconds;
        }

        /// <summary>
        /// 獲取下一微秒時間戳
        /// </summary>
        /// <param name="lastTimestamp"></param>
        /// <returns></returns>
        private static long GetNextTimestamp(long lastTimestamp)
        {
            long timestamp = GetTimestamp();
            if (timestamp <= lastTimestamp)
            {
                timestamp = GetTimestamp();
            }
            return timestamp;
        }

        /// <summary>
        /// 獲取長整形的ID
        /// </summary>
        /// <returns></returns>
        public long GetId()
        {
            lock (syncRoot)
            {
                long timestamp = GetTimestamp();
                if (Snowflake.lastTimestamp == timestamp)
                { //同一微妙中生成ID
                    sequence = (sequence + 1) & sequenceMask; //用&運算計算該微秒內產生的計數是否已經到達上限
                    if (sequence == 0)
                    {
                        //一微妙內產生的ID計數已達上限，等待下一微妙
                        timestamp = GetNextTimestamp(Snowflake.lastTimestamp);
                    }
                }
                else
                {
                    //不同微秒生成ID
                    sequence = 0L;
                }
                if (timestamp < lastTimestamp)
                {
                    throw new Exception("時間戳比上一次生成ID時時間戳還小，故異常");
                }
                Snowflake.lastTimestamp = timestamp; //把當前時間戳儲存為最後生成ID的時間戳
                long Id = ((timestamp - twepoch) << (int)timestampLeftShift)
                    | (datacenterId << (int)datacenterIdShift)
                    | (machineId << (int)machineIdShift)
                    | sequence;
                return Id;
            }

        }
    }

測試程式碼：

class Program
    {
        static void Main(string[] args)
        {
            var blockingCollection = new BlockingCollection<long>();
            List<Task> tasks = new List<Task>();
            for (int i = 0; i < 100; i++)
            {
                var task = Task.Run(() =>
                {

                    for (int j = 0; j < 10000; j++)
                    {

                        //blockingCollection.Add(Snowflake.Instance().GetId());//一臺機器

                        blockingCollection.Add(new Snowflake(1,1).GetId());//多臺機器
                    }
                });

                tasks.Add(task);
            }

            Task.WaitAll(tasks.ToArray());

            Console.WriteLine(blockingCollection.Distinct().Count());

            Console.ReadKey();

        }
    }