【AS3代码】用键盘方向键控制影片拖动

package
{
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.KeyboardEvent;
    import flash.events.TimerEvent;
    import flash.utils.Timer;
    import flash.utils.getTimer;
    
    public class Main extends Sprite
    {    
        var mascot:Bo = new Bo();
        var leftArrow:Boolean = false;
        var rightArrow:Boolean = false;
        var upArrow:Boolean = false;
        var downArrow:Boolean = false;
        
        public function Main():void
        {
            init();
        }
        private function init():void
        {
            this.addChild(mascot);
            stage.addEventListener(KeyboardEvent.KEY_DOWN,downs);
            stage.addEventListener(KeyboardEvent.KEY_UP,ups);
            stage.addEventListener(Event.ENTER_FRAME,moves);
        }
        
        public function downs(e:KeyboardEvent):void
        {
            if(e.keyCode == 37)
            {
                leftArrow = true;
            }
            else if(e.keyCode == 38)
            {
                upArrow = true;
            }
            else if(e.keyCode == 39)
            {
                rightArrow = true;
            }
            else if(e.keyCode == 40)
            {
                downArrow = true;
            }
        }
        
        public function ups(e:KeyboardEvent):void
        {
            if(e.keyCode == 37)
            {
                leftArrow = false;
            }
            else if(e.keyCode == 38)
            {
                upArrow = false;
            }
            else if(e.keyCode == 39)
            {
                rightArrow = false;
            }
            else if(e.keyCode == 40)
            {
                downArrow = false;
            }
        }
        
        public function moves(e:Event):void
        {
            var speed:Number = 15;
            
            if(leftArrow && upArrow)
            {
                mascot.x -= speed;
                mascot.y -= speed;
            }
            
            if(leftArrow)
            {
                mascot.x -= speed;
            }
            else if(upArrow)
            {
                mascot.y -= speed;
            }
            
            if(rightArrow && downArrow)
            {
                mascot.x += speed;
                mascot.y += speed;
            }
            
            if(rightArrow)
            {
                mascot.x += speed;
            }
            else if(downArrow)
            {
                mascot.y += speed;
            }
        }
        
    }
}