namespace 多态之猫咬狗
{//猫叫 完了 狗叫 猫咬了一口老鼠 老鼠叫 猫如果咬狗，狗也叫
    class Program
    {
        static void Main(string[] args)
        {
            Dog d1 = new Dog();
            Cat c1 = new Cat();
            d1.OnBy += new BeiYaoDelegate(d1_Ontong);
            c1.咬(d1, 2);
            //d1.Is被咬();         
            Console.ReadKey();
        }
        static void d1_Ontong()
        {
            Console.WriteLine("狗被咬了 汪！");
        }
    }
    abstract class Animal
    {
        public int Blood { get; set; }
        public abstract void shout();
        public abstract void 咬(Animal an,int blood);
        public event BeiYaoDelegate OnBy;
    }
    class Cat : Animal
    {
        public Cat()
        { 
            Blood = 10; 
        }
        //private BeiYaoDelegate _beiYaoDelegate;
        //public event BeiYaoDelegate OnBy
        //{
        //    add { _beiYaoDelegate += value; }
        //    remove { _beiYaoDelegate -= value; }
        //}
        public new event BeiYaoDelegate OnBy;
        public override void shout()
        {
            Console.WriteLine("喵");
        }
        public override void 咬(Animal an,int blood)
        {
            an.Blood -= blood;
            //if (Blood != 10 && _beiYaoDelegate != null)
            //{
            //    _beiYaoDelegate();
            //}
            if (an.OnBy !=null)
            { an.OnBy(); }

        }
    }
    class Dog : Animal
    {
         public Dog()
        { 
             Blood = 10;
             //while (true)//实时检测自己是否被咬 会死循环 不往下运行！
             //{ Is被咬(); }
         }
         public new event BeiYaoDelegate OnBy;

        public override void shout()
        {
            Console.WriteLine("旺");
        }
        public void Is被咬()
        {
            if (Blood != 10 && OnBy != null)//如何判断被咬
            { OnBy(); }
        }
        public override void 咬(Animal an, int blood)
        {
            an.Blood -= blood;

        }
    }
    class Mouse : Animal
    {

        public Mouse()
        { Blood = 10; }
        public override void shout()
        {
            Console.WriteLine("吱吱");
        }

        public override void 咬(Animal an, int blood)
        {
            throw new NotImplementedException();
        }
    }
    public  delegate void BeiYaoDelegate();//被咬了！  

}