Adobe FLEX 2 - CREATING AND EXTENDING COMPONENTS, Руководство пользователя

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Dispatching custom events 41
Once defined using the
[Event]
metadata tag, you can refer to the event in an MXML file, as
the following example shows:
<?xml version="1.0"?>
<!-- events/MainEventApp.mxml -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
xmlns:MyComp="myComponents.*" >
<mx:Script>
<![CDATA[
import myEvents.EnableChangeEvent;
public function
enableChangedListener(eventObj:EnableChangeEvent):void {
// Handle event.
}
]]>
</mx:Script>
<MyComp:MyButton enableChanged="myTA.text='got event';" />
<mx:TextArea id="myTA" />
</mx:Application>
If you do not identify an event with the
[Event]
metadata tag, the compiler generates an
error if you try to use the event name in MXML. The metadata for events is inherited from
the superclass, however, so you do not need to tag events that are already defined with the
[Event]
metadata tag in the superclass.
Dispatching an event
You use the
dispatchEvent()
method to dispatch an event. The
dispatchEvent()
method
has the following signature:
public dispatchEvent(event:Event):Boolean
This method requires an argument of type Event, which is the event object. The
dispatchEvent()
method initializes the
target
property of the event object with a reference
to the component dispatching the event.
You can create an event object and dispatch the event in a single statement, as the following
example shows:
dispatchEvent(new Event("click"));
You can also create an event object, initialize it, and then dispatch it, as the following example
shows:
var eventObj:EnableChangeEvent = new EnableChangeEvent(" enableChange ");