MACROMEDIA FLEX 2-MIGRATING APPLICATIONS TO FLEX 2 Manuale Utente Scaricare il pdf (Pagina 116)

116 Events

You must also change your code if you created a custom event handler class and defined a

handleEvent() method that listened for all events. Flex implicitly registered this method as a

handler for all events. Functions named

handleEvent() no longer catch all events by default

as they did in Flex 1.x.

For example, if in your application you registered the custom listener with the

addEventListener() method, as follows:

public var myListener:MyEventListener = new MyEventListener();

b1.addEventListener("click", myListener);

You now explicitly register the custom listener’s handleEvent() method for each event you

want to handle, as follows:

public var myListener:MyEventListener = new MyEventListener();

b1.addEventListener(MouseEvent.CLICK, myListener.handleEvent);

Using the EventDispatcher class

The UIComponent class now inherits from the player’s EventDispatcher class. As a result, you

no longer need to mix in the EventDispatcher class when creating new components.

The

dispatchEvent() method now requires an argument of type Event, so you can no

longer construct an event using an Object like

{ type: "click" }. You must now do the

following instead:

dispatchEvent(new MouseEvent(MouseEvent.CLICK));

To dispatch an event from a custom component, you can do the following:

Flex 1.x:

<mx:CustomPanel mouseDown="dispatchEvent({type: 'resizeEvent', size:

'small'})">

Flex 2:

private function mouseDownHandler(event:MouseEvent):void {

var resizePanelEvent:ResizePanelEvent = new

ResizePanelEvent(ResizePanelEvent.RESIZE);

resizePanelEvent resizePanelEvent.size = "small";

dispatchEvent(event);

}

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MACROMEDIA FLEX 2-MIGRATING APPLICATIONS TO FLEX 2 Manuale Utente Pagina 116