监测程序运行的时间，stopWatch

    ArrayList arrInt = new ArrayList();
                 //用stopwatch来计时 运行的时间
             Stopwatch watch = new Stopwatch();
             watch.Start();
             for (int i = ; i < ; i++)
             {
                 arrInt.Add(i);
             }
             watch.Stop();
             Console.WriteLine(watch.Elapsed);
             Console.ReadKey();

            // 使用泛型集合避免装箱和拆箱。
             List<int> arrInt1 = new List<int>();
             Stopwatch watch2 = new Stopwatch();
             watch2.Start();
             for (int i = ; i < ; i++)
             {
                 arrInt1.Add(i);
             }
             watch2.Stop();
             Console.WriteLine(watch.Elapsed);
             Console.ReadKey();