备忘录模式实例1

1、以游戏的场景为例,我们来讲解这个备忘录模式,一游戏角色有生命力、攻击力、防御力等数据,在打Boss后如果效果不理想可以让游戏恢复到决斗前的状态。

2、玩家类

 1 class GameRole
 2     { 
 3     //生命力
 4         public int Vitality { set; get; }
 5     //攻击力
 6         public int Attack { set; get; }
 7     //防御力
 8         public int Defense { set; get; }
 9     //状态显示
10         public void StateDisplay()
11         {
12             Console.WriteLine("显示当前状态:");
13             Console.WriteLine("体力:{0}",this.Vitality);
14             Console.WriteLine("攻击力:{0}",this.Attack);
15             Console.WriteLine("防御力: {0}",this.Defense);
16         }
17     //获得初始状态
18         public void GetInitState()
19         {
20             this.Vitality = 100;
21             this.Attack = 100;
22             this.Defense = 100;
23         }
24     //战斗
25         public void Fight()
26         {
27             this.Vitality = 0;
28             this.Attack = 0;
29             this.Defense = 0;
30         }
31     }
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3、客户端类

 1 static void Main(string[] args)
 2         {
 3             //大战boss前
 4             Console.WriteLine("#############_战boss前_#################");
 5             GameRole gr = new GameRole();
 6             gr.GetInitState();
 7             gr.StateDisplay();
 8 
 9             //通过新的实例来保存进度
10             GameRole backup = new GameRole();
11             backup.Vitality = gr.Vitality;
12             backup.Defense = gr.Defense;
13             backup.Attack = gr.Attack;
14 
15             //战boss后
16             Console.WriteLine("#############_战boss后_#################");
17             gr.Fight();
18             gr.StateDisplay();
19 
20             //恢复之前的状态
21             Console.WriteLine("#############_恢复之前的状态_#################");
22             gr.Vitality = backup.Vitality;
23             gr.Defense = backup.Defense;
24             gr.Attack = backup.Attack;
25             gr.StateDisplay();
26 
27             Console.Read();
28 
29 
30         }
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4、这样写问题主要在于客户端的调用,这样把整个游戏角色的细节暴露给了客户端,你的客户端的职责过大,我们希望可以把这些游戏角色的存取状态细节封装起来,而且最好是封装在外部的类当中,以体现职责分离。

5、到这里我们就要用到备忘模式

定义: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原先保存的状态。

6、现在我们来改造这个代码,首先要有一个存储状态的类

 1 class RoleStateMemento
 2     {
 3         public int Vitality { set; get; }
 4         public int Attack { set; get; }
 5         public int Defense { set; get; }
 6         public RoleStateMemento(int vit, int att, int def)
 7         {
 8             this.Vitality = vit;
 9             this.Attack = att;
10             this.Defense = def;
11 
12         }
13     }
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7、改造玩家类

 1  class GameRole
 2     { 
 3     //生命力
 4         public int Vitality { set; get; }
 5     //攻击力
 6         public int Attack { set; get; }
 7     //防御力
 8         public int Defense { set; get; }
 9 
10     //保存状态
11         public RoleStateMemento SaveState()
12         {
13             return new RoleStateMemento(Vitality, Attack, Defense);
14         }
15 
16     //恢复状态
17         public void RecoveryState(RoleStateMemento rs)
18         {
19             this.Vitality = rs.Vitality;
20             this.Attack = rs.Attack;
21             this.Defense = rs.Defense;
22         }
23     //状态显示
24         public void StateDisplay()
25         {
26             Console.WriteLine("显示当前状态:");
27             Console.WriteLine("体力:{0}",this.Vitality);
28             Console.WriteLine("攻击力:{0}",this.Attack);
29             Console.WriteLine("防御力: {0}",this.Defense);
30         }
31     //获得初始状态
32         public void GetInitState()
33         {
34             this.Vitality = 100;
35             this.Attack = 100;
36             this.Defense = 100;
37         }
38     //战斗
39         public void Fight()
40         {
41             this.Vitality = 0;
42             this.Attack = 0;
43             this.Defense = 0;
44         }
45     }
View Code

8、还要有一个管理角色状态的类

1 class RoleStateCaretaker
2     {
3         public RoleStateMemento rs;
4     }

9、客户端代码

 1 static void Main(string[] args)
 2         {
 3             //大战boss前
 4             Console.WriteLine("#############_战boss前_#################");
 5             GameRole gr = new GameRole();
 6             gr.GetInitState();
 7             gr.StateDisplay();
 8 
 9             //保存进度
10             RoleStateCaretaker rc = new RoleStateCaretaker();
11             rc.roleState = gr.SaveState();
12 
13 
14             //战boss后
15             Console.WriteLine("#############_战boss后_#################");
16             gr.Fight();
17             gr.StateDisplay();
18 
19             //恢复之前的状态
20             Console.WriteLine("#############_恢复之前的状态_#################");
21             gr.RecoveryState(rc.roleState);
22             gr.StateDisplay();
23 
24             Console.Read();
25 
26 
27         }
View Code

 

posted @ 2017-05-08 13:43  爱生活,爱代码  阅读(233)  评论(0编辑  收藏  举报