using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Publisher publisher = new Publisher();  

        Subscriber subscriber = new Subscriber(publisher);  

        publisher.method();

    }

}

​

public class Publisher

{

    public event EventHandler ev;

    public void OnChange(object s, EventArgs e)

    {

        if(ev!=null)

        {

            ev(this,e);

        }

    }

    public void method()

    {

        OnChange(this, EventArgs.Empty);

    }

}

​

​

public class Subscriber

{

    private Publisher publishers;  

    public Subscriber(Publisher publisher)  

    {  

        this.publishers = publisher;  

        publishers.ev += publishers_ProdcutAddedInfo;  

    } 

    public void publishers_ProdcutAddedInfo(object sender, EventArgs e)

    {

        Console.WriteLine("adf");

        if(sender!= null)

        {

        Console.WriteLine("aadf");

         }

    }

}

////////////////////////

public class Subscriber

{

    private Publisher publishers;  

    public Subscriber(Publisher publisher)  

    {  

        this.publishers = publisher;  

        publishers.ev += publishers_ProdcutAddedInfo;  

    } 

    public void publishers_ProdcutAddedInfo(object sender, EventArgs e)

    {

        Console.WriteLine("adf");

        if(sender!= null)

        {

        Console.WriteLine("aadf");

         }

    }

}