装饰者模式

　　　　Decorator模式结构图

Food.cs//抽象基类(Componet)

        abstract public class Food
       {

 　　 public string foodName;
        public double price;
        virtual public string GetName() { return foodName; }
        abstract public double GetCost();

      }

Decorator.cs//装饰者类(Decorator)

　　abstract public class Decorator : Food
    {
    }

Marmite.cs//被装饰的类(ConcreteComponet1)

　　public class Marmite : Food//砂锅
    {
        public Marmite()
        {
            this.foodName = "marmite";
            this.price = 4.0;
        }
        public override string GetName()
        {
            return this.foodName;
        }
        public override double GetCost()
        {
            return price;
        }
    }

Rice.cs//被装饰的类(ConcreteComponet2)

　　public class Rice : Food//米饭
    {
        public Rice()
        {
            this.foodName = "rice";
            this.price = 1.0;
        }
        public override string GetName()
        {
            return this.foodName;
        }
        public override double GetCost()
        {
            return price;
        }
    }

Rib.cs//具体装饰者(ConcreteDecoratorA)

　　public class Rib : Decorator//小排
    {
        Food food;
        public Rib(Food food)
        {
            this.food = food;
            this.foodName = "rib";
            this.price = 5.0;
        }
        public override string GetName()
        {
            return food.GetName() + "," + foodName;
        }
        public override double GetCost()
        {
            return food.GetCost() + price;
        }
    }

Ham.cs//具体装饰者(ConcreteDecoratorB)

　　public class Ham : Decorator
    {
        Food food;
        public Ham(Food food)//火腿
        {
            this.food = food;
            this.price = 2.0;
            this.foodName = "ham";
        }
        override public string GetName()
        {
            return food.GetName() + "," + foodName;
        }
        public override double GetCost()
        {
            return food.GetCost() + price;
        }
    }

 

 

Test:

　　 static void Main(string[] args)
        {
            Rice rice = new Rice();
            Ham ham = new Ham(rice);
            Rib rib = new Rib(ham);
            Console.WriteLine("菜单: {0}", rib.GetName());
            Console.WriteLine("总价: {0}", rib.GetCost());
        }

Result: 菜单: rice,ham,rib

           总价: 8