结构型设计模式之外观模式

 1 using System;
 2 
 3     class SubSystem_class1 
 4     {
 5         public void OperationX() 
 6         {
 7             Console.WriteLine("SubSystem_class1.OperationX called");
 8         }
 9     }
10 
11     class SubSystem_class2
12     {
13         public void OperationY()
14         {
15             Console.WriteLine("SubSystem_class2.OperationY called");
16         }
17     }
18 
19     class SubSystem_class3 
20     {
21         public void OperationZ()
22         {            
23             Console.WriteLine("SubSystem_class3.OperationZ called");
24         }    
25     }
26 
27     class Facade 
28     {
29         private SubSystem_class1 c1 = new SubSystem_class1();
30         private SubSystem_class2 c2 = new SubSystem_class2();
31         private SubSystem_class3 c3 = new SubSystem_class3();
32 
33         public void OperationWrapper()
34         {
35             Console.WriteLine("The Facade OperationWrapper carries out complex decision-making");
36             Console.WriteLine("which in turn results in calls to the subsystem classes");
37             c1.OperationX();
38             if (1==1 /*some really complex decision*/)
39             {
40                 c2.OperationY();
41             }
42             // lots of complex code here . . .
43             c3.OperationZ();
44         }
45         
46     }
47 
48     /// <summary>
49     ///    Summary description for Client.
50     /// </summary>
51     public class Client
52     {
53           public static int Main(string[] args)
54         {
55             Facade facade = new Facade();
56             Console.WriteLine("Client calls the Facade OperationWrapper");
57             facade.OperationWrapper();      
58             return 0;
59         }
60     }