设计模式 之 观察者--委托与事件

标签：c#   设计模式   delegate   

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace 委托
{
    //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

        //声明委托
        public delegate void BoiledEventHandler(object sender, BoiledEventArgs e);
        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;
            }
        }

        //可以供集成自Heater的类重写，以便继承类拒绝其他对象对它的监视
        protected virtual void OnBoiled(BoiledEventArgs e) {
            if (Boiled != null) {
                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)
                {
                    //建立BoiledEventArgs对象
                    BoiledEventArgs e = new BoiledEventArgs(temperature);
                    OnBoiled(e);//调用OnBolied方法
                }
            }
        }
    }


        //警报器
        public class Alarm {
            public void MakeAlert(object sender, Heater.BoiledEventArgs e)
            {
                Heater heater = (Heater)sender;
                //访问sender中的公共字段
                Console.WriteLine("Alarm:{0} - {1}: ", heater.area,heater.type);
                Console.WriteLine("Alarm:滴滴滴，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) {
                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(string[] args)
            {
                Heater heater = new Heater();
                Alarm alarm = new Alarm();

                heater.Boiled += alarm.MakeAlert;//注册方法
                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
            }
        }
    
}

简述委托：

设计模式 之 观察者--委托与事件

标签：c#   设计模式   delegate   

原文地址：http://blog.csdn.net/ry513705618/article/details/41418171