红包随机金额
static void Main(string[] args) { double totalAmount = 20; int num = 10; double minAmount = 0.01; Random r = new Random(); for (int i = 1; i < num; i++) { double safeAmount = (totalAmount - (num - i) * minAmount) / (num - i); //double money = new Random().Next(Convert.ToInt32(minAmount * 100), Convert.ToInt32(safeAmount * 100)) / 100; double money = NextDouble(r, minAmount * 100, safeAmount * 100) / 100; money = Math.Round(money, 2, MidpointRounding.AwayFromZero); totalAmount=totalAmount-money; totalAmount = Math.Round(totalAmount, 2, MidpointRounding.AwayFromZero); Console.WriteLine("第" + i + "个红包:" + money + " 元,余额:" + totalAmount + " 元"); } Console.WriteLine("第" + num + "个红包:" + totalAmount + " 元,余额:0 元"); Console.ReadKey(); } /// <summary> /// 生成设置范围内的Double的随机数 /// eg:_random.NextDouble(1.5, 2.5) /// </summary> /// <param name="random">Random</param> /// <param name="miniDouble">生成随机数的最大值</param> /// <param name="maxiDouble">生成随机数的最小值</param> /// <returns>当Random等于NULL的时候返回0;</returns> protected static double NextDouble(Random random, double miniDouble, double maxiDouble) { if (random != null) { return random.NextDouble() * (maxiDouble - miniDouble) + miniDouble; } else { return 0.0d; } }