【C#设计模式(17)——迭代器模式(Iterator Pattern)】

前言

迭代器模式可以使用统一的接口来遍历不同类型的集合对象，而不需要关心其内部的具体实现。

代码

//迭代器接口
public interface Iterator
{bool HashNext();object Next();
}
//集合接口
public interface Collection
{Iterator CreateIterator();
}
//元素迭代器
public class ElementIterator : Iterator
{private string[] elements;private int index = 0;public ElementIterator(string[] elements){this.elements = elements;}public bool HashNext(){return index < elements.Length;}public object Next(){if (index < elements.Length){return elements[index++];}return null;}
}//元素集合
public class ElementCollection : Collection
{private string[] elements;public ElementCollection(string[] elements){this.elements = elements;}public Iterator CreateIterator(){return new ElementIterator(elements);}
}/** 行为型模式：Behavioral Pattern * 迭代器模式：Iterator Pattern*/
internal class Program
{static void Main(string[] args){string[] elements = { "A", "B", "C", "D", "E", "F",};Collection collection = new ElementCollection(elements);Iterator iterator = collection.CreateIterator();while(iterator.HashNext()){Console.WriteLine(iterator.Next().ToString());}Console.ReadLine();}
}

结果