Decorator

 

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

namespace ConsoleApplication2
{
    //componnent
    abstract class libraryitem
    {
        private int numbers;
        public int Numbers
        {
            get { return numbers; }
            set { numbers = value; }
        }
        public abstract void display();
    }
    //concretecomponent

    class book : libraryitem
    {
        private string author;
        public book(string author, int numbers)
        {
            this.author = author;
            this.Numbers = numbers;
        }
        public override void display()
        {
            Console.WriteLine("\nBook----------");
            Console.WriteLine("author {0}", author);
            Console.WriteLine("numbers{0}", Numbers);
        }
    }


    //decorator

    abstract class decorate : libraryitem
    {
        protected libraryitem libraryitem;
        public decorate(libraryitem libraryitem)
        {
            this.libraryitem = libraryitem;
        }

        public override void display()
        {
            libraryitem.display();
        }
    }
    //conceredecorator
    class borrowable : decorate
    {
        protected ArrayList borrwoers = new ArrayList();
        public borrowable(libraryitem libraryitem)
            : base(libraryitem)
        { }
        public void borrowitem(string name)
        {
            borrwoers.Add(name);
            libraryitem.Numbers--;
        }
        public void returnitem(string name)
        {
            borrwoers.Remove(name);
            libraryitem.Numbers++;
        }

        public override void display()
        {
            base.display();
            foreach (string borrower in borrwoers)
            {
                Console.WriteLine("borrowers:{0}", borrower);
            }
        }
    }
    //conceredecorator
    class colorable : decorate
    {
        private string color;
        public colorable(libraryitem libraryitem)
            : base(libraryitem)
        {

        }
        public void setColor(string color)
        {
            this.color = color;
        }
        public override void display()
        {
            base.display();

            Console.WriteLine("book's color{0}",color);
        }
    }

}