读张子阳老师的委托和事件 2

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace 张子阳事件
 7 {
 8     //定义委托
 9     public delegate void GreetingDelegate(string name);
10 
11     public class GreetingManager
12     {
13         //public void GreetPeople(string name,GreetingDelegate MakeGreeting)
14         //{
15         //    MakeGreeting(name);
16         //}
17 
18 
19 
20         //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
21 
22         public GreetingDelegate MakeGreeting1;
23         //与字段对比缺少封装过程 ，怎么像字段那样能封装委托变量！
24 
25         //......................................怎么封装呢 ？？？
26 
27         //然后传个下面的方法 ，实现面向对象的设计思路
28         public void GreetPeople(string name)
29         {
30             if (MakeGreeting1 != null)//如果有方法注册委托变量
31             {
32                 MakeGreeting1(name);  //通过委托调用方法
33             }
34         }
35 
36 
37 
38         //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
39         private string makeString;//这相当委托
40 
41         public string MakeString //这相当事件，它封装了委托类型的变量
42         {
43             get { return makeString; }
44             set { makeString = value; }
45         }
46         public void GreetString()
47         {
48             if (makeString != null)
49             {
50                 Console.WriteLine(makeString);
51             }
52         }
53         //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
54 
55 
56         //这一次我们在这里声明一个事件  和 声明委托变量对比 
57         // public       GreetingDelegate MakeGreet;
58         public event GreetingDelegate MakeGreet;//对事件的声明 实际是 声明一个私有的委托变量
59         public void GreetPeople1(string name)
60         {
61             MakeGreet(name);
62         }
63 
64     }
65 }

View Code

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace 张子阳事件
 7 {
 8     
 9     class Program
10     {
11       
12         static void Main(string[] args)
13         {
14             GreetingManager gm = new GreetingManager();
15             // gm.MakeGreeting1 = EnglishGreeting; // public 下能赋值！
16             gm.MakeGreeting1 += ChineseGreeting;//把方法加到委托里
17             gm.GreetPeople("Jimmy Zhang");      //注意，这次不需要再传递 delegate1变量
18             //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
19             gm.MakeString = "String__!";
20             gm.GreetString();
21             //~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
22            
23             //gm.MakeGreet = EnglishGreeting;//事件“张子阳事件.GreetingManager.MakeGreet”只能出现在 += 或 -= 的左边(从类型“张子阳事件.GreetingManager”中使用时除外)    //  = 不能进行赋值！
24             gm.MakeGreet += EnglishGreeting;  
25             gm.MakeGreeting1("张子阳");
26 
27 
28 
29             Console.ReadKey();
30         }
31 
32 
33 
34         private static void EnglishGreeting(string name)
35         {
36             Console.WriteLine("Morning, " + name);
37         }
38 
39         private static void ChineseGreeting(string name)
40         {
41             Console.WriteLine("早上好, " + name);
42         }
43     }
44 }

View Code

加上了一些个人整理