C#事件

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace ClassTrining
 7 {
 8     class 事件
 9     {
10         class Demo
11         {
12             /// <summary>
13             /// 实例化事件处理类并测试事件
14             /// </summary>
15             /// <param name="args"></param>
16             static void Test(string[] args)
17             {
18                 //实例化事件处理类对象
19                 Counter c = new Counter(new Random().Next(10));
20                 //添加事件
21                 c.ThresholdReached += c_ThresholdReached;
22 
23                 Console.WriteLine("press ‘a‘ key to increase total");
24                 while (Console.ReadKey(true).KeyChar == ‘a‘)
25                 {
26                     Console.WriteLine("adding one");
27                     c.Add(1);
28                 }
29             }
30             /// <summary>
31             /// 实例事件处理方法
32             /// </summary>
33             /// <param name="sender">事件来源对象</param>
34             /// <param name="e">事件数据对象</param>
35             static void c_ThresholdReached(object sender, ThresholdReachedEventArgs e)
36             {
37                 Console.WriteLine("The threshold of {0} was reached at {1}.", e.Threshold, e.TimeReached);
38                 Environment.Exit(0);
39             }
40         }
41 
42         /// <summary>
43         /// 事件处理类
44         /// </summary>
45         class Counter
46         {
47             private int threshold;
48             private int total;
49 
50             public Counter(int passedThreshold)
51             {
52                 threshold = passedThreshold;
53             }
54 
55             public void Add(int x)
56             {
57                 total += x;
58                 if (total >= threshold)
59                 {
60                     //声明事件数据
61                     ThresholdReachedEventArgs args = new ThresholdReachedEventArgs();
62                     args.Threshold = threshold;
63                     args.TimeReached = DateTime.Now;
64                     //调用虚函数处理事件数据
65                     OnThresholdReached(args);
66                 }
67             }
68             /// <summary>
69             /// 虚方法,可以被子类重载
70             /// </summary>
71             /// <param name="e"></param>
72             protected virtual void OnThresholdReached(ThresholdReachedEventArgs e)
73             {
74                 //泛型事件委托
75                 EventHandler<ThresholdReachedEventArgs> handler = ThresholdReached;
76                 if (handler != null)
77                 {
78                     //this代表事件来源，e代表不包含事件数据的对象
79                     handler(this, e);
80                 }
81             }
82             /// <summary>
83             /// 事件委托方法
84             /// </summary>
85             public event EventHandler<ThresholdReachedEventArgs> ThresholdReached;
86         }
87 
88         /// <summary>
89         /// 处理事件数据类
90         /// </summary>
91         public class ThresholdReachedEventArgs : EventArgs
92         {
93             public int Threshold { get; set; }
94             public DateTime TimeReached { get; set; }
95         }
96     }
97 }