装饰者模式-

1、个人理解：将主类中的不定个数的、无序的额外处理划分为多个类，在客户端的时候能够对这些额外处理随意与主体类进行组织。

看一段代码（根据别人的Java代码改的）：卖饼，手抓饼和肉夹馍两种，可以添加的辅料有煎蛋、肉松等。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace 装饰者模式2
{
    class Program
    {
        static void Main(string[] args)
        {
            Test test = new Test();
            test.test();
        }
    }

    public abstract class Pancake
    {
        public string desc = "我不是一个具体的饼";
        public double price = 0;

        public string GetDesc()
        {
            return desc;
        }
    }

    /// <summary>
    /// 手抓饼
    /// </summary>
    public class TornCake : Pancake
    {
        public TornCake()
        {
            desc = "手抓饼";
            price = 4;
        }
    }
    /// <summary>
    /// 肉夹馍
    /// </summary>
    public class Roujiamo : Pancake
    {
        public Roujiamo()
        {
            desc = "肉夹馍";
            price = 6;
        }
    }

    /// <summary>
    /// 作料
    /// </summary>
    public abstract class Condiment : Pancake
    {
        protected Pancake pancake;
        public abstract string getDesc();
        public abstract void AddCondiment(Pancake pancake);
    }
    /// <summary>
    /// 煎蛋
    /// </summary>
    public class FiredEgg : Condiment
    {
        public FiredEgg()
        {
            price = 1;
            desc = "煎蛋";
        }
        public override string getDesc()
        {
            return pancake.GetDesc() + ", 加煎蛋";
        }

        public override void AddCondiment(Pancake pancake)
        {
            this.pancake = pancake;
            pancake.price += price;
            pancake.desc += ", 加" + desc;
        }
    }
    /// <summary>
    /// 黄瓜
    /// </summary>
    public class Cucumber : Condiment
    {
        public Cucumber()
        {
            price = 2;
            desc = "黄瓜";
        }
        public override string getDesc()
        {
            return pancake.GetDesc() + ", 加" + desc; ;
        }
        public override void AddCondiment(Pancake pancake)
        {
            this.pancake = pancake;
            pancake.price += 2;
            pancake.desc += ", 加黄瓜";
        }
    }

    class Test
    {
        public void test()
        {
            Pancake pancake = new TornCake();
            //手抓饼基础价
            Console.WriteLine("描述:{0}, 基础价格:{1}", pancake.GetDesc(), pancake.price);

            Pancake roujiamo = new Roujiamo();
            //肉夹馍基础价
            Console.WriteLine("描述:{0}, 基础价格:{1}", roujiamo.GetDesc(), roujiamo.price);
            FiredEgg fireEgg = new FiredEgg();
            Cucumber Cucumber = new Cucumber();
            fireEgg.AddCondiment(roujiamo);
            Cucumber.AddCondiment(roujiamo);

            Console.WriteLine("描述:{0}, 价格:{1}", roujiamo.GetDesc(), roujiamo.price);

            Console.ReadLine();
        }
    }
}

View Code