C# ArrayList数组的用法

ArrayList al = new ArrayList();
            for (int i = 0; i < 3; i++)
            {
                al.Add(i);
          }
                   foreach (int obj in al)//或foreach (object obj in al),因为al是一个object类型的数组
            {
                Response.Write(obj+"-OK"+"<br>");
            }
 ArrayList和Array相互之间的转化
         (1)以下是把ArrayList数组中的值拷贝到Array中去的实例用法
          //int[] IResult=new int[al.Count];
            //al.CopyTo(IResult);
            //或是用下面的方法
          int[] IResult = (int[])al.ToArray(typeof(Int32));//ToArray(Int32);这样错误,一定要强制类型转换
          //Person[] personArrayFromList = (Person[])personList.ToArray(typeof(Person));  
         foreach(int item   in IResult)
            {
              Response.Write(item.ToString());
            }
Response.Write("以下是把Array数组中的值拷贝到ArrayList中去的实例用法" + "<br>" + "结果为:<br>");
            int[] a ={ 222, 333, 555 };
            ArrayList arrList = new ArrayList();
            foreach (object obj in a)//或foreach (int obj in a)
            {
                arrList.Add(obj);
                Response.Write(obj+"<br>");
            }