备忘录模式(Memento Pattern)

备忘录模式(Memento Pattern)

介绍
在不破坏封装性的前提下,捕获一个对象的内部状态,并在该对象之外保存这个状态。这样以后就可将该对象恢复到保存的状态。

示例
有一个Message实体类,某个对象对它的操作有Insert()方法,只有在插入时间符合要求的情况下才能插入成功,因此要求可以保存和恢复Message对象的状态,插入失败后则恢复Message对象的状态,然后只更新时间,再次插入。
1.jpg.png
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.Memento
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(Memento
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


MessageModelCaretaker

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.Memento
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    
/// Memento管理者(Caretaker
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif    
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif    
public class MessageModelCaretaker
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif    {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
private MessageModel _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        
/// Message实体对象(Memento
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public MessageModel MessageModel
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            
get { return _messageModel; }
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            
set { _messageModel = 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


SqlMessage

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.Memento
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    
/// Sql方式操作MessageOriginator
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif    
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif    
public class SqlMessage
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.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/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        
/// <summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// 插入Message
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// <param name="mm">Message实体对象</param>
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// <returns></returns>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public bool Insert(MessageModel mm)
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            
// 秒数可以被5整除时,则执行插入操作
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
            if (mm.PublishTime.Second % 5 == 0)
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                
// 代码略
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
                return true;
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 false;
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        
/// 保存Memento
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 SaveMemento()
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            
return new MessageModel(_message, _publishTime);
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        
/// 恢复Memento
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
/// </summary>
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif        
/// <param name="mm"></param>
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
public void RestoreMemento(MessageModel mm)
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            
this._message = mm.Message;
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            
this._publishTime = mm.PublishTime;
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 Pattern.Memento;
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
http://www.cnblogs.com/Images/OutliningIndicators/None.gif
public partial class Memento : 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        SqlMessage m = 
new SqlMessage();
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        m.Message = "Message
内容";
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        m.PublishTime = DateTime.Now;
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        MessageModelCaretaker mmc = 
new MessageModelCaretaker();
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        mmc.MessageModel = m.SaveMemento();
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
bool bln = false;
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif        
while (!bln)
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif        {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            bln = m.Insert(
new MessageModel(m.Message, m.PublishTime));
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            Response.Write(m.Message + " " + m.PublishTime.ToString() + " " + bln.ToString());
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            Response.Write("<br />");
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif            
if (!bln)
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif            {
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                System.Threading.Thread.Sleep(1000);
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                m.RestoreMemento(mmc.MessageModel);
http://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif                m.PublishTime = DateTime.Now;
http://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockEnd.gif            }
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
Message内容 2007-5-23 21:32:13 False
Message内容 2007-5-23 21:32:14 False
Message内容 2007-5-23 21:32:15 True

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