行为型设计模式之命令模式

 1 using System;
 2 
 3     abstract class Command 
 4     {
 5         abstract public void Execute();
 6         protected Receiver r;
 7         public Receiver R
 8         {
 9             set 
10             {
11                 r = value; 
12             }
13         }
14     }
15 
16     class ConcreteCommand : Command
17     {
18         override public void Execute()
19         {
20             Console.WriteLine("Command executed");
21             r.InformAboutCommand();
22         }
23     }
24 
25     class Receiver 
26     {
27         public void InformAboutCommand()
28         {
29             Console.WriteLine("Receiver informed about command");
30         }
31         
32     }
33 
34     class Invoker 
35     {
36         private Command command;
37         public void StoreCommand(Command c)
38         {
39             command = c;
40         }
41         public void ExecuteCommand()
42         {
43             command.Execute();
44         }        
45     }
46 
47     /// <summary>
48     ///    Summary description for Client.
49     /// </summary>
50     public class Client
51     {
52         public static int Main(string[] args)
53         {        
54             // Set up everything
55             Command c = new ConcreteCommand();
56             Receiver r = new Receiver();
57             c.R = r;
58             Invoker i = new Invoker();
59             i.StoreCommand(c);
60 
61             // now let application run
62 
63             // the invoker is how the command is exposed for the end-user 
64             // (or a client) initiates the command, 
65             // (e.g. toolbar button, menu item)
66 
67             i.ExecuteCommand();
68 
69             return 0;
70         }
71     }