delegate void MyDelegate();

void Method1()
{
//this is a method
}


void Method2()
{
//this is another method
}



//here we are creating a a new object and attaching Method1 to it.
MyDelegate dlg1 = new MyDelegate(Method1);


//now attaching another method

dlg1+= Method2;


//If you call the delegate now, all the methods refered by it will be executed.


dlg1( );

//Method1 and Method2 are executed in the same order as they are attached to the delegated.

using System;

namespace ConsoleApplication45
{
    class SalesItem
    {
        int stock;

        public delegate void onLowStock(); //delegate that holds StockLow events
        public event onLowStock StockLow;  //StockLow event is attached to the delegate onLowStock
        
        public SalesItem(int stock)
        {
            this.stock = stock;
        }

        public void Add(int qty)
        {
            stock += qty;
        }

        public void Remove(int qty)
        {
            if (stock < qty)
            {
                StockLow();   //calling the event
            }
            stock -= qty;
        }
    }
    class Program
    {
        static void Main(string[] args)
        {

            SalesItem s1 = new SalesItem(10);
            s1.StockLow += new SalesItem.onLowStock(s1_StockLow); //new event handler is attached to the StockLow event
            s1.Remove(5);
            s1.Add(2);
            s1.Remove(25);


        }

        static void s1_StockLow()
        {
            Console.WriteLine("Item s1 is out of stock");
        }
    }
}