Why to use events somewhere where method is enough?

I read some events tutorial and just do not get what is the benefit in simple code like this..method should be used the same way:

class Bulb

{ public delegate void handler();
  public event handler Glowing;
 ...
  Glowing+=SomeMethod;
  private void TurnOn
  {
    Glowing();
  }

  pri开发者_JAVA百科vate void SomeMethod
  {
  }

}

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Simply Events allow others using your code to perform some custom Implementation they want when that Event occurs (when Bulb is Glowing).

Simply calling your method won't tell anybody that something has happened.

Events are very basic Element of any Event Driven Programming

If your program doesn't need to tell about an event you don't need to implement such Functionality. However having such functionality has benefits.

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For Example when using a List Class you dont know when an Item got added to it (if at some point some other code does that) but in a ObservableCollection you get notifications when Items are Added or Removed.

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An event is a message sent by an object to signal the occurrence of an action. The action could be caused by user interaction, such as a mouse click, or it could be triggered by some other program logic.

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The idea is that a different class which can hold Three different Bulbs can get notified by the event (if it implements a handler) that the light has been turned on and is Glowing.

So the benefit does not reside in the simply class but in what ever classes/objects are going to be holding/using instances of the Bulb class.

Hope that made some sense :)

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Events over methods become handy when you have a class dependency that needs to know or be notified about a stateful change:

public class Lamp
{
    Bulb inThelamp = new Bulb();
    inTheLamp.Glowing += myLampMethod;

    // If these arguments have been defined for this event that is
    public void myLampMethod(object sender, EventArgs e) 
    {
        // Code to react to the light suddenly being on
    }
}

This allows the Lamp class to recognize that something has turned the bulb on. In many cases it will be through some action in the Lamp (click, pushknob, etc). But in some cases it could be an external class that calls a public Bulb property directly without using the Lamp itself (such is if(PowerCompany.BillsPaid) Lamp.BulbInTheLamp.TurnedOn();). This is all assuming that the modifiers are set to allow this kind of access.

The point is that it allows notification of an occurrence rather than requiring that a particular method be called manually each time you want an action to occur.