using System;

using System.Collections.Generic;

​

//public delegate void EventHandler(object sender, EventArgs ev) ;

​

public class CustomEventArgs

{

    private string message;

    public CustomEventArgs(string s)

    {

        this. Message  = s;

    }

​

    public string Message {get;set;} 

}

class Publisher

{

    // Declare the event using EventHandler<T>

    public event EventHandler<CustomEventArgs> Event;

    public void DoSomething()

    {

        Console.WriteLine(88);

        OnRaiseCustomEvent(new CustomEventArgs("Did something"));

    }

​

    protected virtual void OnRaiseCustomEvent(CustomEventArgs e)

    {

        if (Event != null)

        {

            // Format the string to send inside the CustomEventArgs parameter

            e.Message += String.Format(" at {0}", DateTime.Now.ToString());

            // Use the () operator to raise the event.

            Event(this, e);

        }

    }

}

class Subscriber

{

    private string id;

    public Subscriber(string ID, Publisher pub)

    {

        id = ID;

        // Subscribe to the event using C# 2.0 syntax

        pub.Event += HandleCustomEvent;

    }

​

    // Define what actions to take when the event is raised.

    void HandleCustomEvent(object sender, CustomEventArgs e)

    {

        Console.WriteLine(id + " received this message: {0}", e.Message);

    }

}

​

public class Program

{

    public static void Main(string[] args)

    {

        Publisher pub = new Publisher();

        Subscriber sub1 = new Subscriber("sub1", pub);

        Subscriber sub2 = new Subscriber("sub2", pub);

        // Call the method that raises the event.

        pub.DoSomething();

    }

}