User Guide

List component 463
List.change
Availability
Flash Player 6 (6.0 79.0).
Edition
Flash MX 2004.
Usage
Usage 1:
on(change){
// your code here
}
Usage 2:
listenerObject = new Object();
listenerObject.change = function(eventObject){
// your code here
}
listInstance.addEventListener("change", listenerObject)
Description
Event; broadcast to all registered listeners when the selected index of the list changes as a result of
user interaction.
The first usage example uses an
on() handler and must be attached directly to a List instance.
The keyword
this, used inside an on() handler attached to a component, refers to the
component instance. For example, the following code, attached to the List instance
myBox, sends
“_level0.myBox” to the Output panel:
on(click){
trace(this);
}
The second usage example uses a dispatcher/listener event model. A component instance
(
listInstance) dispatches an event (in this case, change) and the event is handled by a function,
also called a handler, on a listener object (
listenerObject) that you create. You define a method
with the same name as the event on the listener object; the method is called when the event is
triggered. When the event is triggered, it automatically passes an event object (
eventObject) to
the listener object method. Each event object has properties that contain information about the
event. You can use these properties to write code that handles the event. For more information,
see “EventDispatcher class (API)” on page 415.
Finally, you call the
addEventListener() method on the component instance that broadcasts
the event to register the listener with the instance. When the instance dispatches the event, the
listener is called.