实现对象集合枚举接口

//UserCollection users = new UserCollection();

//((ArrayList)users.GetEnumerator()).RemoveAt(0);

//IEnumerator iterator = users.GetEnumerator();

//while (iterator.MoveNext())

//    Console.WriteLine(iterator.Current);

//foreach (object obj in users)

//    Console.WriteLine(obj);

//MyEnumrator myEnum = new MyEnumrator(new ArrayList() { "AAa", "bCCC" });

//如果实现了MoveNext方法，Current属性等，就可以通过下面的方法遍历对象集合；实际上，此时，刚好正是实现了接口IEnumerator。

//while (myEnum.MoveNext())

//    Console.WriteLine(myEnum.Current);