Why do event handlers always have a return type of void?

Question

Hey, I wondered why is it that the return type of events such as

private void button1_Click(object sender, EventArgs e)

is always void?

Answer 1

the default EventHandler delegate defined this signature. However, you are free to create your own events with your own return types if you wish.

public class AnEvent
{
  public delegate MyReturnType MyDelegateName();
  public event MyDelegateName MyEvent;

  public void DoStuff()
  {
    MyReturnType result = null;
    if (MyEvent != null)
      result = MyEvent();
    Console.WriteLine("the event was fired");
    if (result != null)
      Console.Writeline("the result is" + result.ToString());
  }
}

public class EventListener
{
  public EventListener()
  {
    var anEvent = new AnEvent();
    anEvent.MyEvent += SomeMethod;
  }

  public MyReturnType SomeMethod()
  {
    Console.Writeline("the event was handled!");
    return new MyReturnType;
  }
}