行为型设计模式之策略模式

 1 using System;
 2 
 3     
 4     abstract class Strategy 
 5     {
 6         abstract public void DoAlgorithm();
 7     }
 8 
 9     class FirstStrategy : Strategy 
10     {
11         override public void DoAlgorithm()
12         {
13             Console.WriteLine("In first strategy");            
14         }
15     }
16 
17     class SecondStrategy : Strategy 
18     {
19         override public void DoAlgorithm()
20         {
21             Console.WriteLine("In second strategy");            
22         }
23     }
24 
25     class Context 
26     {
27         Strategy s;
28         public Context(Strategy strat)
29         {
30             s = strat;            
31         }
32 
33         public void DoWork()
34         {
35             // some of the context‘s own code goes here
36         }
37 
38         public void DoStrategyWork()
39         {
40             // now we can hand off to the strategy to do some 
41             // more work
42             s.DoAlgorithm();
43         }
44     }
45 
46     /// <summary>
47     ///    Summary description for Client.
48     /// </summary>
49     public class Client
50     {
51         public static int Main(string[] args)
52         {    
53             FirstStrategy firstStrategy = new FirstStrategy();
54             Context c = new Context(firstStrategy);
55             c.DoWork();
56             c.DoStrategyWork();
57 
58             return 0;
59         }
60     }