装修设计模式怎么写

public abstract class Home
    {
        public string description = "空房子";
        public abstract string getDescription();

        public Double Area;
        public abstract Double getArea();
    }

    //房子
    public class House : Home
    {
        public House()
        {
            description = "MyHouse:";
        }

        public override string getDescription()
        {
            return description;
        }

        public override Double getArea()
        {
            return 0.0;
        }
    }

    //主卧
    public class MainCell : Home 
    {
        Home home;

        public MainCell(Home home,Double area)
        {
            this.home = home;
            this.Area = area;
        }

        public override string getDescription()
        {
            return this.home.getDescription() + " MainCell";
        }

        public override Double getArea()
        {
            return this.Area + home.getArea(); 
        }
    }

    //阳台
    public class Balcony : Home
    {
        Home home;

        public Balcony(Home home, Double area)
        {
            this.home = home;
            this.Area = area;
        }

        public override string getDescription()
        {
            return this.home.getDescription() + " Balcony";
        }

        public override Double getArea()
        {
            return this.Area + home.getArea();
        }
    }

//测试代码

//创建一个空房子，初期面积0
Home myHouse = new House();

//在房子上装饰一个主卧
myHouse = new MainCell(myHouse, 20);
//在房子上装饰一个主卧
myHouse = new MainCell(myHouse, 20);
//在房子上装饰一个阳台
myHouse = new Balcony(myHouse, 15);

Console.WriteLine(myHouse.getDescription());
Console.WriteLine("Area:" + myHouse.getArea());

//输入结果
MyHouse: MainCell MainCell Balcony
Area:55