AS 2.0:

new FrameDelay(init);
Stage.align = “TL”;
Stage.scaleMode = “noScale”;
sizeListener = new Object();
sizeListener.onResize = function() {
trace(Stage.width);
trace(Stage.height);
txt_width=Stage.width;
txt_height=Stage.height;
trace (width);

onderkant._x = Stage.width – 691;
Afb_mc._x = Stage.width – 267;

};
Stage.addListener(sizeListener);
stop();

This is really great news today….

private function init(e:Event = null):void
{
removeEventListener(Event.ADDED_TO_STAGE, init);
// entry point

stage.scaleMode = StageScaleMode.EXACT_FIT;
var grafico:Grafico = new Grafico();

grafico.Desenhar();
grafico.x = (stage.stageWidth – grafico.width) / 2;
grafico.y = (stage.stageHeight – grafico.height) / 2;

addChild(grafico);
}

Hope that it heps.

public function Main():void {
stage.align = StageAlign.TOP_LEFT;
stage.scaleMode = StageScaleMode.NO_SCALE;
this.loaderInfo.addEventListener(Event.COMPLETE, init);
}
private function init(e:Event):void {
if (stage.stageWidth == 0 || stage.stageHeight == 0) {
stage.addEventListener(Event.RESIZE, init);
} else {
// Init stuff goes here!
}
}

If it’s not serving and the document class then I assume this is the code you are using:
var d:Demo = new Demo(); <– at this point the DisplayObject doesn’t get a reference to stage
addChild(d); <– at this point the DisplayObject does have a reference to stage.

The stage reference gets set on DisplayObjects once they are added to the stage.

I get why they did this, and DisplayObject shouldn’t know anything about the stageWidth or stageHeight, before it is added to a certain stage. Just as the DisplayObject doesn’t have a parent before it is added to the Display List.

But I also understand why you expect stage to be defined, because for all intents and purposes the stage object is a global variable and should be accessible by any subclass of DisplayObject. Problem is when do you set the stage reference. In the DisplayObject constructor, of course…. Wait… The DisplayObject is an abstract class and a call the the constructor throws an ArgumentError.

So the only logical place to set it is when a DisplayObject is added to the stage.