CSharpEventSample.cs

using System;
using System.Collections.Generic;

public class SampleEventArgs : EventArgs
{
    public int x { get; private set; }
    public int y { get; private set; }

    public SampleEventArgs(int x, int y) : base()
    {
        this.x = x;
        this.y = y;
    }
}

public delegate void SampleEventHandler(object sender, SampleEventArgs eventArgs);

public class Sender
{
    event SampleEventHandler OnCalc;
    public void eventStart(int x, int y)
    {
        OnCalc(this, new SampleEventArgs(x, y));
    }

    public Sender(List<Receiver> receivers)
    {
        foreach (var receciver in receivers)
            OnCalc += receciver.Add;
    }

}

public class Receiver
{
    public void Add(object sender, SampleEventArgs eventArgs)
    {
        if (eventArgs != null)
        {
            Console.WriteLine(eventArgs.x + eventArgs.y);
            Console.Read();
        }
    }
}

public class Program
{
    static void Main(string[] args)
    {
        List<Receiver> receiverList = new List<Receiver>();
        receiverList.Add(new Receiver());
        Sender sender = new Sender(receiverList);
        sender.eventStart(1, 2);
    }
}