Move the circle in as3 - actionscript-3

Question

I already have the graphic with image on the screen and I wanted to it to move when I pressed the arrows on keyboard.
But it seems the listener is not running and there is no error.
Here is the code:
package
{
import flash.display.Loader;
import flash.display.Sprite;
import flash.events.Event;
import flash.display.BitmapData;
import flash.events.KeyboardEvent;
import flash.ui.Keyboard;
import flash.net.URLRequest;
/**.
* ....
* #author Kaoru
*/
[SWF(width = '800', height = '600', backgroundColor = '#000000', frameRate = '24')]
public class GameManager extends Sprite
{
var myBitmap:BitmapData;
var imgLoader:Loader;
var circle:Sprite;
public function GameManager():void
{
circle = new Sprite();
imgLoader = new Loader();
imgLoader.load(new URLRequest("../lib/fira_front.png"));
imgLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, drawImage);
addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown);
}
private function drawImage(e:Event):void
{
myBitmap = new BitmapData(imgLoader.width, imgLoader.height, false);
myBitmap.draw(imgLoader);
circle.graphics.beginBitmapFill(myBitmap, null, true);
circle.graphics.drawCircle(50, 50, 10);
circle.graphics.endFill();
addChild(circle);
}
private function onKeyDown(e:KeyboardEvent):void
{
if (e.keyCode == Keyboard.LEFT)
{
circle.x += 5;
}
else if (e.keyCode == Keyboard.RIGHT)
{
circle.x -= 5;
}
if (e.keyCode == Keyboard.UP)
{
circle.y += 5;
}
else if (e.keyCode == Keyboard.DOWN)
{
circle.y -= 5;
}
}
}
}

Answer 1

You need to add it to stage like so,
stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown);
I have modified your code like so:
Always check for ADDED_TO_STAGE first and then proceed,
public function GameManager():void
{
addEventListener(Event.ADDED_TO_STAGE, onAddedToStage);
}
private function onAddedToStage(e:Event):void
{
circle = new Sprite();
imgLoader = new Loader();
imgLoader.load(new URLRequest("../lib/fira_front.png"));
imgLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, drawImage);
stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown); //This line is modified
removeEventListener(Event.ADDED_TO_STAGE, onAddedToStage);
}

Answer 2

Have you tried to add your listener on the stage directly ?
So that this
public function GameManager():void
{
circle = new Sprite();
imgLoader = new Loader();
imgLoader.load(new URLRequest("../lib/fira_front.png"));
imgLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, drawImage);
addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown);
}
Becomes this
public function GameManager():void
{
circle = new Sprite();
imgLoader = new Loader();
imgLoader.load(new URLRequest("../lib/fira_front.png"));
imgLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, drawImage);
stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown);
}