可变阴影矩形--（make thing move）DropShadowFilter

package  {
import flash.display.Sprite;
import flash.events.Event;
import flash.filters.DropShadowFilter;

public class AnimatedFilters extends Sprite {

private var filter:DropShadowFilter;
private var sprite:Sprite;

public function AnimatedFilters() {
// constructor code
init();
}

private function init():void{
sprite = new Sprite();
sprite.graphics.lineStyle(2);
sprite.graphics.beginFill(0xffff00);
sprite.graphics.drawRect(-50,-50,100,100);//前两个参数是相对位置，即矩形实际位置为150,150
sprite.graphics.endFill();
sprite.x=200;
sprite.y=200;
addChild(sprite);

filter = new DropShadowFilter(0,0,0,1,20,20,.3);

addEventListener(Event.ENTER_FRAME,onEnterFrame);
}

private function onEnterFrame(event:Event):void
{
var dx:Number = mouseX - sprite.x;
var dy:Number = mouseY - sprite.y;

filter.distance = -Math.sqrt(dx*dx+dy*dy)/10;
filter.angle = Math.atan2(dy,dx)*180/Math.PI;
sprite.filters = [filter];
}

}

}