超类可以在哪个事件阶段引用其派生类中潜在的现有组件？

class SuperComponent extends DragStack {

   private var _childReference:UIComponent;

   public function SuperComponent() {
      // ???
      addEventListener(FlexEvent.CREATION_COMPLETE, onCreationComplete);
   }

   private function onCreationComplete(e:FlexEvent):void {
      //The \'this[]\' technique doesn\'t seem to work and causes run-time errors:
      //trace(\"Component found: \" + this[\"myButton\"]);
   }
}

<!-- Component ChildComponent.mxml -->
<mx:SuperComponent>
  <mx:Button id=\"myButton\" label=\"Press Me!\" />
</mx:SuperComponent>

<mx:SuperComponent>
  <mx:myProperty>
  <mx:Button id=\"myButton\" label=\"Press Me!\" />
 </mx:myProperty>
</mx:SuperComponent>

myButton

this[\"myButton\"]

getChildByName()

\"myButton\"