ArrayList list=new ArrayList();
            int i;
            for(i=1;i<=10;i++)
            {
                Random rani = new Random(unchecked((int)DateTime.Now.Ticks+i));
                list.Add(rani.Next(1, 100));
            }
            //Console.WriteLine(list[0]);
            Console.ReadKey();

伪随机数，初始化一次就可以了

Random rani = new Random();
ArrayList list = new ArrayList();
int i;
            
for (i = 1; i <= 10; i++)
{   
    list.Add(rani.Next(1, 100));
}