using System;using System.Collections.Generic;using System.Text;
namespace Delegate { // 热水器 public class Heater { private int temperature; public string type = "RealFire 001"; // 添加型号作为演示 public string area = "China Xian"; // 添加产地作为演示
public delegate void BoiledEventHandler(Object sender, BoiledEventArgs e); //声明委托 public event BoiledEventHandler Boiled; //声明事件
// 定义BoiledEventArgs类，传递给Observer所感兴趣的信息 public class BoiledEventArgs : EventArgs { public readonly int temperature; public BoiledEventArgs(int temperature) { this.temperature = temperature; } }
// 可以供继承自 Heater 的类重写，以便继承类拒绝其他对象对它的监视 protected virtual void OnBolied(BoiledEventArgs e) { if (Boiled != null) { //如果有对象注册 Boiled(this, e); //调用所有注册对象的方法 } } // 烧水。 public void BoilWater() { for (int i = 0; i <= 100; i++) { temperature = i; if (temperature > 95) { BoiledEventArgs e = new BoiledEventArgs(temperature); OnBolied(e); } } } }
// 警报器 public class Alarm { public void MakeAlert(Object sender, Heater.BoiledEventArgs e) { Heater heater = (Heater)sender; //这里是不是很熟悉呢？ //访问 sender 中的公共字段 Console.WriteLine("Alarm：{0} - {1}: ", heater.area, heater.type); Console.WriteLine("Alarm: 嘀嘀嘀，水已经 {0} 度了：", e.temperature); Console.WriteLine(); }
}
// 显示器 public class Display { public static void ShowMsg(Object sender, Heater.BoiledEventArgs e) { //静态方法 Heater heater = (Heater)sender; Console.WriteLine("Display：{0} - {1}: ", heater.area, heater.type); Console.WriteLine("Display：水快烧开了，当前温度：{0}度。", e.temperature); Console.WriteLine(); } }
class Program { static void Main() { Heater heater = new Heater(); Alarm alarm = new Alarm();
heater.Boiled += alarm.MakeAlert; //注册方法 heater.Boiled += (new Alarm()).MakeAlert; //给匿名对象注册方法 heater.Boiled += new Heater.BoiledEventHandler(alarm.MakeAlert); //也可以这么注册 heater.Boiled += Display.ShowMsg; //注册静态方法
heater.BoilWater(); //烧水，会自动调用注册过对象的方法 } }
本文为转载
转载于:https://www.cnblogs.com/wolfcool/archive/2009/06/16/1504576.html
