using System;

​

public class Program

{

    public static void Main()

    {

        Item item = new Item(1,"T-Shirt",500,20);

        Console.WriteLine("Enter the no of T-Shirt units are available");

        int val= int.Parse(Console.ReadLine());

        item.StockInHand = val;

        Console.WriteLine(item.StockInHand.ToString());

    }

​

    public class Item

    {

        public int ItemId {get;set;}

        public string Name {get ;set;}

        public int Price {get ;set;}  

        int stockinhand;

        public Order order;

​

​

        public int StockInHand

        {

            get { return stockinhand;}

            set {

                    if (value < 5)

                    {

                        order.RefillRequest +=new EventHandler(RefillRequestHandler);

                        order.InitiateRefillRequest();

                    }

                stockinhand = value;

            }

        }

​

        public Item(int itemid,string name,int price,int stockinhand)

        {

            this.order = new Order();

            this.ItemId = itemid;

            this.Name = name;

            this.Price = price;

            this.StockInHand = stockinhand;

        }

​

        public void RefillRequestHandler(object sender, EventArgs e)

        {

            Console.WriteLine("T-Shirt units has been reduced less than 5");

        }

    }

​

    public delegate void EventHandler(object sender, EventArgs e);

​

    public class Order

    {

        public event EventHandler RefillRequest;

        public Order()

        {

        }

        public void InitiateRefillRequest()

        {

           OnstockInHandReduced();

        }

​

        protected virtual void OnstockInHandReduced()

        {

            if (RefillRequest != null)

            RefillRequest.Invoke(this, null);

        }

​

        public void RefillRequestHandler(object sender, EventArgs e)

        {

            Console.WriteLine("code executed");

            Console.ReadLine();

        }

    }

}

​