根据权重/百分比获取概率值

public int GetAward()
        {
            int result = 0;
          var timeSpanAwardList = new List<Award>();
            var timeList = new List<object>() {};
            timeSpanAwardList.ForEach(t =>
            {
                if (t.DailyQuantity <= 100) //如果每日已发数量>=每日可发数量就排除抽奖列表
                {
                    timeSpanAwardList.Remove(t);
                }
            });
            //当前可参与抽奖的奖品的设置总数
            if (timeSpanAwardList.Count > 0)
            {
                var countRangeList = new List<List<int>>();
                //当前所有奖品总数累加和
                var currentAllTotalCount = 0;
                //计算奖品范围基数值
                foreach (var item in timeSpanAwardList)
                {
                    countRangeList.Add(new List<int>
                    {
                        currentAllTotalCount + 1,
                        currentAllTotalCount + item.TotalQuantity
                    });
                    currentAllTotalCount += item.TotalQuantity;
                }
                //根据百分比重新计算随机基数//这里默认百分比100%
                var baseCount = int.Parse(Math.Ceiling(currentAllTotalCount/(100/100.0)).ToString(CultureInfo.InvariantCulture));
                //以所有奖品总数累加和为上限，1为下限，随机出一位数
                var randomNum = new Random().Next(1, baseCount + 1);
                //奖品序号
                int? awardIndex = null;
                for (var i = 0; i < countRangeList.Count; i++)
                {
                    //判断随机数是否在某个范围基数内，奖品总数范围值越大，中奖几率越高
                    if (countRangeList[i][0] <= randomNum && countRangeList[i][1] >= randomNum)
                    {
                        //如果在范围内，则为奖品序号赋值
                        awardIndex = i;
                        break;
                    }
                }
                if (awardIndex.HasValue)
                {
                    //根据奖品序号取得奖品Id，并获取奖品信息返回
                 result= timeSpanAwardList[awardIndex.Value].Id;

                }
            }
            return result;
        }

public class Award
    {
        public int Id { get; set; }
    /// <summary>
    /// 每日抽中次数
    /// </summary>
        public int DailyQuantity { get; set; }
    /// <summary>
    /// 库存
    /// </summary>
        public int TotalQuantity { get; set; }
   }