Assembly: System.Web.Extensions (in System.Web.Extensions.dll)
Raising an event invokes the event handler through a delegate. For more information, see Consuming Events.
The method also enables derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.Notes to Inheritors
When you override the method in a derived class, make sure that you call the method for the base class so that registered delegates receive the event.