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();
        }
        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();
        }