配置抽奖几率,实现随机抽奖

定义奖品类型类

Class PrizeType

{

　　public int Probability {get; set;}

　　public int Quantity {get; set;}

　　public int RandId {get; set;}

　　public string PrizeName {get; set;}

}

 

var allPrizeList = new List<PrizeType>();

allPrizeList.Add(new PrizeType(){Probability = 5000, Quantity = 10, PrizeName = "奖1", RandId = 0});

allPrizeList.Add(new PrizeType(){Probability = 4000, Quantity = 10, PrizeName = "奖2", RandId = 1});

allPrizeList.Add(new PrizeType(){Probability = 1000, Quantity = 10, PrizeName = "奖3", RandId = 2});

 

public PrizeType getRand()

{

　　PrizeType prize = null;

　　int result = -1, proSum = 1, indexResult = 0;

　　var dicRand = new Dictionary<int, int>();

　　int[] proArr = new int[dateSource.Count];

　　

　　for (int i=0; i<dateSourcePrizeList.Count; i++)

　　{

　　　　proArr[i] = dataSourcePrizeList[i].Probability;

　　}

 

　　var arr = proArr.OrderBy(s => s);

 

　　foreach(int val in arr)

　　{

　　　　dicRand[proSum] = indexResult ++;

　　　　proSum += val;

　　}

　　int length = proArr.Length;
　　Random ran = new Random(Guid.NewGuid().GetHashCode());
　　int ranNum = ran.Next(1, proSum);

　　//计算随机数所在的分组序号
　　result = dicRand.Where(a => a.Key <= ranNum).OrderByDescending(a => a.Key).FirstOrDefault().Value;

 

　　prize = allPrizeList.FirstOrDefault(a => a.RandId == result);

　　return prize;

}