1 /* 2  * Window系统可能会异常终止，设计一个系统备份程序。类WindowsSystem是 3  * 发起人角色(Orignation)，类Memento是备忘录角色(Memento)，类User是 4  * 备忘录管理角色(Caretaker)。应用备忘录模式，用C#控制台应用程序实现 5  * 该设计。 6  */ 7 using System; 8 using System.Collections.Generic; 9 using System.Linq;10 using System.Text;11 12 namespace Memento13 {14     //Orignation15     class WindowsSystem16     {17         private string systemstate;18         public string SystemState19         {20             get { return systemstate; }21             set { systemstate = value; }22         }23         public Memento SaveState()24         {25             return (new Memento(systemstate));26         }27         public void RecoveryState(Memento memeto)28         {29             this.systemstate = memeto.SystemState;30         }31         public void Show()32         {33             Console.WriteLine("当前系统状态："+systemstate);34         }35     }36     //Memento37     class Memento38     { 39         private string systemstate;40         public Memento(string systemstate)41         {42             this.systemstate = systemstate;43         }44         public string SystemState45         {46             get { return systemstate; }47         }48     }49     //Caretaker50     class User51     {52         private Memento memento;53         public Memento MementoFunc54         {55             get { return memento; }56             set { memento = value; }57         }58     }59     class Program60     {61         static void Main(string[] args)62         {63             //系统正常64             Console.WriteLine("系统启动");65             WindowsSystem ws = new WindowsSystem();66             ws.SystemState = "正常";67             ws.Show();68             //备份69             Console.WriteLine("系统备份");70             User user = new User();71             user.MementoFunc = ws.SaveState();72             //系统崩溃73             Console.WriteLine("系统崩溃");74             ws.SystemState = "崩溃";75             ws.Show();76             //系统恢复77             Console.WriteLine("系统恢复");78             ws.RecoveryState(user.MementoFunc);79             ws.Show();80         }81     }82 }