设计模式(C#)之迭代器模式(Iterator Pattern)

设计模式(C#)之迭代器模式(Iterator Pattern)

代码下载

1.概念
提供一种方法顺序访问一个聚合对象中各个元素，而又不需暴露该对象的内部表示。
2.类图

3.代码

Model.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace IteratorPattern
{
    public class Model
    {

        public string ID
        {
            get;
            set;

        }

        public string Name
        {
            get;
            set;

        }
    }
}

ICollection.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace IteratorPattern
{
    public interface  ICollection
    {
        /// <summary>
        /// 得到迭代对象
        /// </summary>
        /// <returns></returns>
        Iiterator GetIterator();
    }
}

Collection.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace IteratorPattern
{
    public class Collection : ICollection
    {
        private List<Model> list = new List<Model>();

        /// <summary>
        /// 创建迭代器对象
        /// </summary>
        /// <returns></returns>
        public Iiterator GetIterator()
        {
            return new Iterator(this);
        }

        /// <summary>
        /// 集合内的对象总数
        /// </summary>
        public int Count
        {
            get { return list.Count; }
        }

        /// <summary>
        /// 索引器
        /// </summary>
        /// <param name="index">index</param>
        /// <returns></returns>
        public Model this[int index]
        {
            get { return list[index]; }
            set { list.Add(value); }
        }

    }
}

Iiterator.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;

namespace IteratorPattern
{
    public interface Iiterator
    {
       
        Model  Current { get; }

        Model MoveNext();

        Model First();
    }
}

Iterator.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace IteratorPattern
{
    public class Iterator : Iiterator
    {
        private Collection _collection;
        private int _current = 0;

        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="collection"></param>
        public Iterator(Collection collection)
        {
            this._collection = collection;
        }

        /// <summary>
        /// 第一个对象
        /// </summary>
        /// <returns></returns>
        public Model First()
        {
            _current = 0;
            return _collection[_current];
        }


        /// <summary>
        /// 下一个对象
        /// </summary>
        /// <returns></returns>
        public Model MoveNext()
        {
            _current += 1;

            if (!IsEnd)
            {
                return _collection[_current];
            }
            else
            {
                return null;
            }

        }

        /// <summary>
        /// 是否迭代完毕
        /// </summary>
        public bool IsEnd
        {
            get { return _current >= _collection.Count ? true : false; }
        }

        /// <summary>
        /// 当前
        /// </summary>
        public Model Current
        {
            get { return _collection[_current]; }
        }

    }
}

测试代码

Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace IteratorPattern
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            Collection collection = new Collection();
            collection[0] = new Model() { ID = "0", Name = "User1" };
            collection[1] = new Model() { ID = "1", Name = "User2" };
            collection[2] = new Model() { ID = "2", Name = "User3" };
            collection[3] = new Model() { ID = "3", Name = "User4" };
            collection[4] = new Model() { ID = "4", Name = "User5" };
            collection[5] = new Model() { ID = "5", Name = "User6" };
            Iterator iterator = new Iterator(collection);
            for (Model mm = iterator.First(); !iterator.IsEnd; mm = iterator.MoveNext())
            {
                this.listBox1.Items.Add("编号：" + mm.ID + "名称：" + mm.Name);
            }

        }
    }
}

4.测试结果

代码下载