C#关于事件的几个好例子

#region
    // 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;
        }
    }

       
   //热水器
    public class Heared {
        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
        private int temperature;
        public delegate void BoidHandler(Object sender, BoiledEventArgs e); //声明委托
        public event BoidHandler BoidEvent;  //声明事件

        // 可以供继承自 Heared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 (BoidEvent != null)
            { // 如果有对象注册
                BoidEvent(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, BoiledEventArgs e)
        {
            Heared heater = (Heared)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,BoiledEventArgs e)
        {   //静态方法
            Heared heater = (Heared)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()
        {
            Heared heater = new Heared();
            Alarm alarm = new Alarm();

            heater.BoidEvent += alarm.MakeAlert;   //注册方法
            heater.BoidEvent += (new Alarm()).MakeAlert;      //给匿名对象注册方法
            heater.BoidEvent += new Heared.BoidHandler(alarm.MakeAlert);    //也可以这么注册
            heater.BoidEvent += 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
        }
    }
#endregion