Showing posts with label Difference between event and delegate. Show all posts
Showing posts with label Difference between event and delegate. Show all posts

Tuesday, 17 January 2012

Difference between event and delegate

Difference between event and delegate?

Event:

1) It is a data member of a type(class/structure)
2)It is declared inside a type(class/structure)
3) It is used to generate notifications which are then passed to methods though
delegates.

delegate:

1)It is a datatype(reference type) that holds references of methods with
some signatures.also called as function pointer.
2)It may or may not be declared inside a class.
3)It is used as the return type of an event and used in passing messages from event to methods.


event-->delegate-->method

example:

namespace dd
{
//delegate declaration
delegate void first();
class cc
{
//event declaration
public first myevent;
}
}

example 2:
button1.Click+=new EventHandler(this.button1_Click);
(Windows Applications)

Click is the event that returns an instance of the EventHandler delegate.
EventHandler delegate has the reference of button1_Click event and that
helps in the communication betwen the Click event and button1_Click method