1 using System;
2 using System.Collections.Generic;
3
4 namespace ConsoleApplication1
5 {
6 internal class Program
7 {
8 private static void Main(string[] args)
9 {
10 while (true)
11 {
12 var s = Console.ReadLine();
13 int i;
14 int.TryParse(s,out i);
15
16 //swtich分支处理
17 switch (i)
18 {
19 case 1:
20 MethodHelper.A();
21 break;
22 case 2:
23 MethodHelper.B();
24 break;
25 case 3:
26 MethodHelper.C();
27 break;
28 }
29
30 //委托处理
31 ActionDic.GetInstance().DoAction(i);
32 }
33 }
34 }
35
36 public class MethodHelper
37 {
38 public static void A()
39 {
40 Console.WriteLine("A");
41 }
42 public static void B()
43 {
44 Console.WriteLine("B");
45 }
46 public static void C()
47 {
48 Console.WriteLine("C");
49 }
50 }
51
52 public sealed class ActionDic
53 {
54 private static readonly ActionDic instance = new ActionDic();
55
56 private ActionDic()
57 {
58 actList = new Dictionary<int, Action>
59 {
60 {1, MethodHelper.A},
61 {2, MethodHelper.B},
62 {3, MethodHelper.C},
63 };
64 }
65 public static ActionDic GetInstance()
66 {
67 return instance;
68 }
69 private readonly Dictionary<int, Action> actList;
70
71 public void DoAction(int act)
72 {
73 Action ar;
74 if (actList.TryGetValue(act, out ar))
75 {
76 ar.Invoke();
77 }
78 }
79 }
80 }
