詳解C#產生隨機數函數的程式碼範例

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace csharp
{
  class Program
  {
    static void Main(string[] args)
    {
      Console.WriteLine("生成随机数\n");
      int randCount = 9;//随机数发的个数
      int randMin = 1;//随机数最小值
      int randMax = 21;//随机数最大值
      int randIndex, flag, temp;
      randIndex = temp = flag = 0;
      Random rand = new Random();
      int[] randArr = new int[randCount];
      randArr[0] = rand.Next(randMin, randMax);
      while (true)
      {
        flag = 0;
        temp = rand.Next(randMin, randMax);
        for (int i = 0; i <= randIndex; i++)
        {
          if (temp == randArr[i])
          {
            flag = 1;
            break;
          }
        }
        if (flag == 1)//如果 flag == 1 则有重复的数字生成。
        {
          continue;
        }
        else if (flag == 0)
        {
          randIndex++;
          randArr[randIndex] = temp;
        }
        if (randIndex >= randCount - 1)//如果达到 randCount 退出循环
        {
          break;
        }
      }
      for (int i = 0; i < randCount; i++)
      {
        Console.WriteLine("arr[" + i + "]=" + randArr[i]);
      }
      Console.WriteLine("\n任意键退出。");
      Console.ReadLine();
    }
  }
}