OOP Error

[punstc]

I'm not sure what I'm missing I can't find anything wrong. Eclipse isn't showing any errors but when I run in Flash I get the following error.

TypeError: Error #1009: Cannot access a property or method of a null object reference.
at AS::Page()
at AS::Background()
at CoreyDouglas()

I have 3 classes The Main being CoreyDouglas where I am initiating a new background which extends my page class.

the 3 classes look like this:

CoreyDouglas:

package {
	import AS.Background;
	
	import flash.display.Sprite;

	public class CoreyDouglas extends Sprite
	{
		private var background:Background;
		public function CoreyDouglas()
		{
			background = new Background("images/background");
			this.addChildAt(background, 0);
		}
	}
}

background:

package AS
{
	import flash.display.Bitmap;
	import flash.display.Loader;
	import flash.events.Event;
	import flash.net.URLRequest;
	
	public class Background extends Page
	{
		private var bgsrc:String;
		private var loader:Loader;
		private var bg:Bitmap;
		private var bgWidth:Number;
		private var bgHeight:Number;
		
		public function Background(src:String)
		{
			super();
			bgsrc = src;
		}
		
		override protected function init(e:Event):void
		{
			loader = new Loader();
			loader.contentLoaderInfo.addEventListener(Event.COMPLETE, onLoadComplete);
			loader.load(new URLRequest(bgsrc));
		}
		
		private function onLoadComplete(e:Event):void
		{
			bg = new Bitmap(e.currentTarget.content);
			bg.smoothing = true;
			
			bgHeight = bg.height / bg.width;
			bgWidth = bg.width / bg.height;
			
			if ((stage.stageHeight / stage.stageWidth) < bgHeight) 
			{
				bg.width = stage.stageWidth;
				bg.height = bgHeight * bg.width;
			} 
			else 
			{
				bg.height = stage.stageHeight;
				bg.width = bgWidth * bg.height;
			}
			addChild(bg);
		}
	}
}

and the Page Class

package AS
{
	import flash.display.Sprite;
	import flash.events.Event;

	public class Page extends Sprite
	{
		public function Page()
		{
			super();
			this.addEventListener(Event.ADDED_TO_STAGE, init);
			stage.addEventListener(Event.RESIZE, onStageResize);
		}
		
		protected function init(e:Event):void {};
		protected function onStageResize(e:Event):void {};
	}
}

This is probably something extremely simple that I can't see. Thanks for your help I appreciate it.

[Medyman]

I think the error is with this.addChildAt(background, 0);. If you're trying to add that object to the stage, you might want to add it to the stage directly.

[punstc]

I found the problem late last night.

It was trying to add The resize event listener on to the stage before it was actually added onto the stage. I moved my addEventListener for the stage resize into the function that listened for ADD_TO_STAGE and then it worked fine.

It was one of those very frustrating problems with an easy solution.

Thanks for looking I appreciate it