C#

if (System.IO.File.Exists(physicalpath+filename))
   {
       System.IO.File.Delete(physicalpath+filename);
   }

btnSave.Click += new System.EventHandler(OnClick_Save);

using System;

public class EventRaisingClass
{
    // holds delegates to all subscribed methods
    public event EventHandler SomethingChanged;

    public void ChangeSomething()
    {
        //
        OnSomethingChanged(EventArgs.Empty);
    }

    protected virtual void OnSomethingChanged(EventArgs e)
    {
        EventHandler eh = SomethingChanged;
        if (eh != null)
            eh(this, e);
    }
}

using System;

public class SubscribingClass
{
    private EventRaisingClass eventRaisingInstance;

    public SubscribingClass()
    {
        eventRaisingInstance = new EventRaisingClass();
        // adds a delegate to the specified method to the event's invocation list
        eventRaisingInstance.SomethingChanged += EventRaisingInstanceSomethingChanged;
    }

    private void EventRaisingInstanceSomethingChanged(object sender, EventArgs e)
    {
        Console.WriteLine("Something Changed");
    }
    public void Update()
    {
        eventRaisingInstance.ChangeSomething();
    }
}