基礎(chǔ)才是重中之重~Dictionary<K,V>里V的設(shè)計決定的性能

 　　　static void Draw()
        {
            int count = 5000000;
            Console.WriteLine("test:{0} feeds", count);

            List<GoldCoinInfo> list = new List<GoldCoinInfo>();
            list.Add(new GoldCoinInfo { Id = 100, GoldValue = 5, LeftCount = count, TotalCount = count });
            var dic = new Dictionary<int, int>();
            int _index = 0;
            Stopwatch sw = new Stopwatch();
            sw.Restart();
            foreach (var gold in list)
            {
                for (int j = 0; j < gold.LeftCount; j++)
                {
                    dic.Add(_index, gold.Id);
                    _index++;
                }
            }
            sw.Stop();
            Console.WriteLine("step1:{0} ms", sw.ElapsedMilliseconds);
            sw.Restart();
            var prizeIndex2 = GenerateRandom(dic.Keys.Max(), 1).FirstOrDefault();
            Console.WriteLine("step3:{0} ms,value:{1}", sw.ElapsedMilliseconds, dic[prizeIndex2]);
            sw.Stop();
        }

  　　　　　var dic = new Dictionary<int, Tuple<int, int>>();
            int _index = 0;
            Stopwatch sw = new Stopwatch();
            sw.Restart();
            foreach (var gold in list)
            {
                for (int j = 0; j < gold.LeftCount; j++)
                {
                    dic.Add(_index, new Tuple<int, int>(gold.Id, gold.GoldValue));
                    _index++;
                }
            }

 　　/// <summary>
    /// sql函數(shù)的擴(kuò)展類
    /// </summary>
    public static class SqlFunctionExtensions
    {

        #region 功能方法
        /// <summary>
        /// 在linq to entity中使用SqlServer.NEWID函數(shù)
        /// </summary>
        public static Guid NewId()
        {
            return Guid.NewGuid();
        }
        #endregion

        #region 擴(kuò)展方法
        /// <summary>
        /// 隨機(jī)排序擴(kuò)展方法
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="source"></param>
        /// <returns></returns>
        public static IQueryable<T> OrderByNewId<T>(this IEnumerable<T> source)
        {
            return source.AsQueryable().OrderBy(d => NewId());
        }
        #endregion

    }