1.红包算法-封装方法
/// <summary>
/// 微信红包算法
/// </summary>
/// <param name="allmoney">红包金额</param>
/// <param name="moneycount">红包数量</param>
/// <returns></returns>
public static string GetMoneys(double allmoney, int moneycount)
{
string retamt = "";
//人均最小金额
double min = 0.01;
if (allmoney < moneycount * min)
return null;
int num = moneycount;
List<double> array = new List<double>();
Random r = new Random();
for (int i = 0; i < num; i++)
{
if (moneycount == 1)
{
moneycount--;
array.Add(Convert.ToDouble(allmoney.ToString("0.0000")));
if (retamt.Length > 0)
{
retamt += ",";
}
retamt += Convert.ToDouble(allmoney.ToString("0.000")).ToString();
}else
{
//保存剩余金额可以足够的去分配剩余的红包数量
double max = (allmoney - (moneycount - 1) * min) / moneycount * 2;
double money = r.NextDouble() * max;
money = Convert.ToDouble((money <= min ? min : money).ToString("0.0000"));
moneycount--;
allmoney -= money;
array.Add(money);
if (retamt.Length > 0)
{
retamt += ",";
}
retamt += money.ToString();
}
}
string ret = string.Join(",", retamt);
//再次随机
return ret;
}
2.调用
//总金额66元红包个数3个
string money= GetMoneys(66, 3);
Response.Write("返回值：" +money);