|
ActionScript 3.0 introduces a single event handling model
that replaces the different event handling mechanisms that existed
in previous versions of ActionScript. The new event model is based
on the Document Object Model (DOM) Level 3 Events Specification.
For developers with experience using the ActionScript
2.0
addListener()
method, it may be helpful to
point out the differences between the ActionScript 2.0 event listener
model and the ActionScript 3.0 event model. The following list describes
a few of the major differences between the two event models:
-
To add event listeners in ActionScript
2.0, you use
addListener()
in some cases and
addEventListener()
in
others, whereas in ActionScript 3.0 you use
addEventListener()
in
all cases.
-
There is no event flow in ActionScript 2.0, which means that
the
addListener()
method can be called only on
the object that broadcasts the event, whereas in ActionScript 3.0
the
addEventListener()
method can be called on
any object that is part of the event flow.
-
In ActionScript 2.0, event listeners can be either functions,
methods, or objects, whereas in ActionScript 3.0, only functions
or methods can be event listeners.
-
The
on(
event
)
syntax
is no longer supported in ActionScript 3.0, so you cannot attach
ActionScript event code to a movie clip. You can only use
addEventListener()
to
add an event listener.
The following example, which listens
for a
MouseEvent.CLICK
event on a Button component
called
aButton
, illustrates the basic ActionScript
3.0 event handling model:
aButton.addEventListener(MouseEvent.CLICK, clickHandler);
function clickHandler(event:MouseEvent):void {
trace("clickHandler detected an event of type: " + event.type);
trace("the event occurred on: " + event.target.name);
}
For more information on ActionScript 3.0 event
handling, see
Programming ActionScript 3.0
. For more information
on ActionScript 3.0 event handling for components, see
Handling events
.
|
|
|
