迭代器模式(Iterator Pattern)

介绍
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。

1.jpg.png

示例
有一个Message实体类,某聚合对象内的各个元素均为该实体对象,现在要提供一种方法顺序地访问这个聚合对象中的各个元素。



MessageModel

http://www.cnblogs.com/Images/OutliningIndicators/None.gifusing System;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Collections.Generic;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Text;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
namespace Pattern.Iterator
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif{
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif    
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif    
/// Message实体类
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif    
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif    
public class MessageModel
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif    {
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 构造函数
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// <param name="msg">Message内容</param>
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// <param name="pt">Message发布时间</param>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public MessageModel(string msg, DateTime pt)
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            
this._message = msg;
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            
this._publishTime = pt;
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        }
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
private string _message;
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// Message内容
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public string Message
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            
get { return _message; }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            
set { _message = value; }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        }
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
private DateTime _publishTime;
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// Message发布时间
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public DateTime PublishTime
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            
get { return _publishTime; }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            
set { _publishTime = value; }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif    }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif}
http://www.cnblogs.com/Images/OutliningIndicators/None.gif


ICollection

http://www.cnblogs.com/Images/OutliningIndicators/None.gifusing System;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Collections.Generic;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Text;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
namespace Pattern.Iterator
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif{
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif    
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif    
/// 集合接口(Aggregate
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif    
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif    
public interface ICollection
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif    {
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 创建迭代器对象
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// <returns></returns>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        IIterator CreateIterator();
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif    }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif}
http://www.cnblogs.com/Images/OutliningIndicators/None.gif


Collection

http://www.cnblogs.com/Images/OutliningIndicators/None.gifusing System;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Collections.Generic;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Text;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
namespace Pattern.Iterator
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif{
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif    
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif    
/// 集合(ConcreteAggregate
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif    
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif    
public class Collection : ICollection
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif    {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
private List<MessageModel> list = new List<MessageModel>();
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 创建迭代器对象
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// <returns></returns>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public IIterator CreateIterator()
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            
return new Iterator(this);
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        }
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 集合内的对象总数
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public int Count
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            
get { return list.Count; }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        }
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 索引器
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// <param name="index">index</param>
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// <returns></returns>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public MessageModel this[int index]
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            
get { return list[index]; }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            
set { list.Add(value); }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        }
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif    }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif}
http://www.cnblogs.com/Images/OutliningIndicators/None.gif


IIterator

http://www.cnblogs.com/Images/OutliningIndicators/None.gifusing System;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Collections.Generic;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Text;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
namespace Pattern.Iterator
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif{
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif    
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif    
/// 迭代器接口(IIterator
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif    
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif    
public interface IIterator
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif    {
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 第一个对象
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// <returns></returns>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        MessageModel First();
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 下一个对象
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// <returns></returns>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        MessageModel Next();
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 当前对象
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        MessageModel CurrentMessageModel { 
get; }
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 是否迭代完毕
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
bool IsDone { get; }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif    }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif}
http://www.cnblogs.com/Images/OutliningIndicators/None.gif


Iterator

http://www.cnblogs.com/Images/OutliningIndicators/None.gifusing System;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Collections.Generic;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Text;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
namespace Pattern.Iterator
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif{
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif    
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif    
/// 迭代器(Iterator
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif    
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif    
public class Iterator : IIterator
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif    {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
private Collection _collection;
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
private int _current = 0;
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
private int _step = 1;
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 构造函数
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// <param name="collection"></param>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public Iterator(Collection collection)
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            
this._collection = collection;
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        }
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 第一个对象
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// <returns></returns>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public MessageModel First()
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            _current = 0;
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            
return _collection[_current];
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        }
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 下一个对象
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// <returns></returns>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public MessageModel Next()
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            _current += _step;
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            
if (!IsDone)
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                
return _collection[_current];
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif            }
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            
else
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                
return null;
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif            }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        }
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 当前对象
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public MessageModel CurrentMessageModel
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            
get { return _collection[_current]; }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        }
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 是否迭代完毕
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public bool IsDone
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            
get { return _current >= _collection.Count ? true : false; }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        }
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 步长
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public int Step
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            
get { return _step; }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            
set { _step = value; }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif    }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif}
http://www.cnblogs.com/Images/OutliningIndicators/None.gif



Test

http://www.cnblogs.com/Images/OutliningIndicators/None.gifusing System;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Data;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Configuration;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Collections;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Web;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Web.Security;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Web.UI;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Web.UI.WebControls;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Web.UI.WebControls.WebParts;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using System.Web.UI.HtmlControls;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
using I = Pattern.Iterator;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
public partial class Iterator : System.Web.UI.Page
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif{
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif    
protected void Page_Load(object sender, EventArgs e)
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif    {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        I::Collection collection = 
new I::Collection();
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        collection[0] = 
new I::MessageModel("1条信息", DateTime.Now);
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        collection[1] = 
new I::MessageModel("2条信息", DateTime.Now);
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        collection[2] = 
new I::MessageModel("3条信息", DateTime.Now);
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        collection[3] = 
new I::MessageModel("4条信息", DateTime.Now);
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        collection[4] = 
new I::MessageModel("5条信息", DateTime.Now);
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        collection[5] = 
new I::MessageModel("6条信息", DateTime.Now);
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        collection[6] = 
new I::MessageModel("7条信息", DateTime.Now);
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        collection[7] = 
new I::MessageModel("8条信息", DateTime.Now);
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        collection[8] = 
new I::MessageModel("9条信息", DateTime.Now);
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        I::Iterator iterator = 
new I::Iterator(collection);
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        iterator.Step = 2;
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
for (I::MessageModel mm = iterator.First(); !iterator.IsDone; mm = iterator.Next())
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            Response.Write(mm.Message);
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            Response.Write("<br />");
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif    }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockEnd.gif}
http://www.cnblogs.com/Images/OutliningIndicators/None.gif


运行结果
第1条信息
第3条信息
第5条信息
第7条信息
第9条信息