C#委托与事件之观察者Observer设计模式

  1 using System;
  2 using System.Collections.Generic;
  3 using System.Linq;
  4 using System.Text;
  5 
  6 namespace dotNet之美__委托与事件__Observer观察者模式2
  7 {
  8     /// <summary>
  9     /// 此例子是：热水器加热水，水温大于95度时报警器响起，显示器显示水温。
 10     /// </summary>
 11     class Program
 12     {
 13         static void Main(string[] args)
 14         {
 15             Heater heater = new Heater();
 16             //订阅事件
 17             heater.Boiled += new Alarm().AlarmAlert;
 18             heater.Boiled += new Display().ShowMsg;
 19             //也可以这样订阅
 20             heater.Boiled += new Heater.BoiledEventHandler(new Alarm().AlarmAlert);
 21             heater.BoilWater();
 22             Console.ReadLine();
 23         }
 24     }
 25     /// <summary>
 26     /// 委托与事件实现:观察者设计模式（两种角色：监视者和被监视者）
 27     /// </summary>
 28     class Heater//被监视者（委托事件发布者）
 29     {
 30         //定义订阅者感兴趣的信息，比如：水温、热水器类型以及产地
 31         //定义水温
 32         private int temperature;
 33         //热水器类型
 34         public string type = "ReadFire 001";
 35         //产地
 36         public string area = "China Guangzhou";
 37         /// <summary>
 38         /// 声明一个委托类型
 39         /// </summary>
 40         /// <param name="sender">发布者对象</param>
 41         /// <param name="e">订阅者感兴趣的信息参数</param>
 42         public delegate void BoiledEventHandler(Object sender,BoiledEventArgs e);
 43         /// <summary>
 44         /// 定义委托事件
 45         /// </summary>
 46         public event BoiledEventHandler Boiled;
 47         /// <summary>
 48         /// 订阅者感兴趣的信息
 49         /// </summary>
 50         public class BoiledEventArgs : EventArgs
 51         {
 52             public readonly int temperature;
 53             public BoiledEventArgs(int temperature)
 54             {
 55                 this.temperature = temperature;
 56             }
 57         }
 58         /// <summary>
 59         /// 触发的事件
 60         /// </summary>
 61         /// <param name="e"></param>
 62         public void OnBoiled(BoiledEventArgs e)
 63         {
 64             if (Boiled != null)
 65             {
 66                 Boiled(this, e);
 67             }
 68         }
 69         /// <summary>
 70         /// 触发动作
 71         /// </summary>
 72         public void BoilWater()
 73         {
 74             for (int i = 0; i <= 100; i++)
 75             {
 76                 this.temperature = i;
 77                 if (this.temperature > 95)
 78                 {
 79                     BoiledEventArgs e = new BoiledEventArgs(this.temperature);
 80                     OnBoiled(e);
 81                 }
 82             }
 83         }
 84     }
 85     /// <summary>
 86     /// 订阅者
 87     /// </summary>
 88     class Alarm
 89     {
 90         /// <summary>
 91         /// 报警
 92         /// </summary>
 93         /// <param name="sender">发布者即被监视者对象</param>
 94         /// <param name="e">感兴趣的信息</param>
 95         public void AlarmAlert(Object sender, Heater.BoiledEventArgs e)
 96         {
 97             Heater heater = (Heater)sender;
 98             Console.WriteLine("Alarm:{0}-{1}", heater.area, heater.type);
 99             Console.WriteLine("Alarm:嘀嘀嘀···水温：" + e.temperature);
100         }  
101     }
102     /// <summary>
103     /// 订阅者
104     /// </summary>
105     class Display
106     {
107         /// <summary>
108         /// 显示温度
109         /// </summary>
110         /// <param name="sender">发布者即被监视者对象</param>
111         /// <param name="e">感兴趣的信息</param>
112         public void ShowMsg(Object sender, Heater.BoiledEventArgs e)
113         {
114             Heater heater = (Heater)sender;
115             Console.WriteLine("Display:{0}-{1}", heater.area, heater.type);
116             Console.WriteLine("水快被烧开了，水温：" + e.temperature);
117         }  
118     }
119 }