/// <summary>

    /// 抽象聚合接口

    /// </summary>

    public interface IListCollection

    {

        Iterator GetIterator();

    }

    //迭代器抽象类

    public interface Iterator

    {

        bool MoveNext();

        Object GetCurrent();

        void Next();

        void Reset();

    }

    public class ConcreteList : IListCollection

    {

        int[] collection;

        public ConcreteList()

        {

            collection = new int[] { , , ,  };

        }

        public Iterator GetIterator()

        {

            return new ConcreteIterator(this);

        }

        public int Length

        {

            get { return collection.Length; }

        }

        public int GetElement(int index)

        {

            return collection[index];

        }

    }

    public class ConcreteIterator : Iterator

    {

        private ConcreteList _list;

        private int _index;

        public ConcreteIterator(ConcreteList list)

        {

            _list = list;

            _index = ;

        }

        public bool MoveNext()

        {

            if (_index < _list.Length)

            {

                return true;

            }

            return false;

        }

        public Object GetCurrent()

        {

            return _list.GetElement(_index);

        }

        public void Reset()

        {

            _index = ;

        }

        public void Next()

        {

            if (_index < _list.Length)

            {

                _index++;

            }

        }

    }

    class Program

    {

        static void Main(string[] args)

        {

            Iterator iterator;

            IListCollection list = new ConcreteList();

            iterator = list.GetIterator();

            while (iterator.MoveNext())

            {

                int i = (int)iterator.GetCurrent();

                Console.WriteLine(i.ToString());

                iterator.Next();

            }

            Console.Read();

        }

    }