.Net行为型设计模式之迭代器模式（Iterator）

// 客户端（Client）
static void Main(string[] args)
{
    Iterator iterator;
    ITroopQueue list = new ConcreteTroopQueue();
    iterator = list.GetIterator();

    while (iterator.MoveNext())
    {
        string ren = (string)iterator.GetCurrent();
        Console.WriteLine(ren);
        iterator.Next();
    }

    Console.Read();
}

// 部队队列的抽象聚合类--该类型相当于抽象聚合类Aggregate
public interface ITroopQueue
{
    Iterator GetIterator();
}

// 迭代器抽象类
public interface Iterator
{
    bool MoveNext();
    Object GetCurrent();
    void Next();
    void Reset();
}

//部队队列具体聚合类--相当于具体聚合类ConcreteAggregate
public sealed class ConcreteTroopQueue : ITroopQueue
{
    private string[] collection;

    public ConcreteTroopQueue()
    {
        collection = new string[] { "黄飞鸿", "方世玉", "洪熙官", "严咏春" };
    }

    public Iterator GetIterator()
    {
        return new ConcreteIterator(this);
    }

    public int Length
    {
        get { return collection.Length; }
    }

    public string GetElement(int index)
    {
        return collection[index];
    }
}

// 具体迭代器类
public sealed class ConcreteIterator : Iterator
{
    // 迭代器要集合对象进行遍历操作，自然就需要引用集合对象
    private ConcreteTroopQueue _list;
    private int _index;

    public ConcreteIterator(ConcreteTroopQueue list)
    {
        _list = list;
        _index = 0;
    }

    public bool MoveNext()
    {
        if (_index < _list.Length)
        {
            return true;
        }
        return false;
    }

    public Object GetCurrent()
    {
        return _list.GetElement(_index);
    }

    public void Reset()
    {
        _index = 0;
    }

    public void Next()
    {
        if (_index < _list.Length)
        {
            _index++;
        }

    }
}

public interface IEnumerator
 {
      object Current
      {
           get;
      }

     bool MoveNext();

     void Reset();
 }

public interface IEnumerable
{
    IEumerator GetEnumerator();
}