策略模式的实现

   class Program
    {
        static void Main(string[] args)
        {
            Duck duck = new MiniDuck();
            duck.fly();
            FlyBehavior Fly = new FlyRocketPowered();
            duck.SetFlyBehavior=Fly;
            duck.fly();
        }
    }


    public abstract   class Duck 
    {
        public FlyBehavior flyBehavior;
        public void fly()
        {
            flyBehavior.fly();
        }
        public FlyBehavior SetFlyBehavior
        {
            set 
            {
                this.flyBehavior = value;
            }
        }
    }

    public class MiniDuck:Duck
    {
        public MiniDuck()        
        {
            this.flyBehavior = new FlyWithWing();
        }
    }

    /// <summary>
    /// 飞行的接口申明
    /// </summary>
    public interface  FlyBehavior 
    {
         void fly();
    }

    /// <summary>
    /// 实现飞行的接口
    /// </summary>
    public class FlyWithWing : FlyBehavior 
    {
        public void fly() 
        {
            Console.Write("我是能飞的");
        }
    }

    public class FlyRocketPowered : FlyBehavior 
    {
        public void fly() 
        {
            Console.Write("有火箭带也能飞");
        }
    }