不重复随机数的产生问题

        /// <summary>
        /// 随机生成
        /// </summary>
        /// <param name="RedCount">最小值</param>
        /// <param name="BlueCount">最大值</param>
        /// <param name="LotteryName">个数</param>
        /// <returns></returns>
        private List<int> getRandomNum(int MinNumber,int MaxNumber,int Count)
        {
              List<int> result = new List<int>(Count);     
              Random random = new Random();     
               int temp = 0; 
            
            while (result.Count < Count)     
            {      
                temp = random.Next(MinNumber, MaxNumber+1);
                if (MaxNumber > 9)//3d除外
                {
                    if (!result.Contains(temp))//去重
                    {
                        result.Add(temp);
                    }
                }
                else
                {
                    result.Add(temp);
                }
            }  
            return result; 
        }
        /// <summary>
        /// 随机双色球投注号
        /// </summary>
        /// <param name="RedCount">红球个数</param>
        /// <param name="BlueCount">篮球个数</param>
        /// <returns>投注号</returns>
        private string getSSQBetNumber(int RedCount,int BlueCount)
        {
            List<int> RedList = getRandomNum(1, 33, RedCount);
            RedList.Sort();
            StringBuilder sbR = new StringBuilder();
            foreach (var item in RedList)
            {
                if (item < 10)
                    sbR.Append("0" + item.ToString());
                else
                    sbR.Append(item.ToString());
                sbR.Append(BetDivision);

            }
            StringBuilder sbB = new StringBuilder();
            List<int> BlueList = getRandomNum(1, 15, BlueCount);
            foreach (var item in BlueList)
            {
                if (item < 10)
                    sbB.Append("0" + item.ToString());
                else
                    sbB.Append(item.ToString());
                sbB.Append(BetDivision);
            }
            return sbR.ToString().Substring(0, sbR.ToString().Length - 1) + BetJoint + sbB.ToString().Substring(0, sbB.ToString().Length - 1);
        }

　　灵感来于http://zhoufoxcn.blog.51cto.com/792419/380423/