第七回 基础才是重中之重~通过人类的生活来学习Delegate

一个人（people)，在他60岁之后，就宣布进入晚年了，在这个期间要多注意身体，多体检。

namespace NET基础才是重中之重

{
    /// <summary>
    /// 人类
    /// </summary>
    public class People
    {
        private int age;
        public string name = "张占占";       //姓名
        public string gander = "男";         // 性别

        #region 构造方法
        public People(string _name, string _gander)
        {
            name = _name;
            gander = _gander;
        }
        public People() { }
        #endregion

        //声明委托
        public delegate void LifedEventHandler(Object sender, LifedEventArgs e);
        public event LifedEventHandler Liefd; //声明事件

        /// <summary>
        /// 定义LifedEventArgs类
        /// 传递给Observer所感兴趣的信息
        /// </summary>
        public class LifedEventArgs : EventArgs
        {
            public readonly int temperature;
            public LifedEventArgs(int age)
            {
                this.temperature = age;
            }
        }

        /// <summary>
        /// 可以供继承自 People 的类重写
        /// 以便继承类拒绝其他对象对它的监视
        /// </summary>
        /// <param name="e"></param>
        protected virtual void OnLife(LifedEventArgs e)
        {
            if (Liefd != null)
            {
                Liefd(this, e);  // 调用所有注册对象的方法
            }
        }

        /// <summary>
        /// 生活
        /// </summary>
        public void Life()
        {
            for (int i = 0; i <= 70; i++)
            {
                age = i;
                if (age > 60)
                {
                    LifedEventArgs e = new LifedEventArgs(age);
                    OnLife(e);
                }
            }
        }
    }

    /// <summary>
    /// 警报您了
    /// </summary>
    public class Alarm
    {
        public void MakeAlert(Object sender, People.LifedEventArgs e)
        {
            People heater = (People)sender;
            //访问 sender 中的公共字段
            Console.WriteLine("Alarm：{0} - {1}: ", heater.gander, heater.name);
            Console.WriteLine("Alarm: 您已经 {0} 岁了：", e.temperature);
            Console.WriteLine();
        }
    }

    /// <summary>
    /// 显示信息
    /// </summary>
    public class Display
    {
        public static void ShowMsg(Object sender, People.LifedEventArgs e)
        {   //静态方法
            People heater = (People)sender;
            Console.WriteLine("Display：{0} - {1}: ", heater.gander, heater.name);
            Console.WriteLine("Display：您已经进行晚年了，{0}岁要注意身体了。", e.temperature);
            Console.WriteLine();
        }
    }

    class Program
    {
        static void Main()
        {
            People heater = new People("张占占", "男");
            Alarm alarm = new Alarm();
            heater.Liefd += alarm.MakeAlert;   //注册方法
            heater.Liefd += Display.ShowMsg;       //注册静态方法
            heater.Life();   //会自动调用注册过对象的方法
            Console.ReadKey();
        }
    }
}