拖动,缓动,加投影效果(提供源码下载)

/**
* ...
* @author lby
* @version 0.1
*/

package lbynet{

        import flash.display.Sprite;
        import flash.display.InteractiveObject;
        import flash.events.MouseEvent;
        import flash.events.Event;

        import flash.filters.DropShadowFilter;

        public class Drop {

                private var loop:int;
                private var grav:Number;
                private var can:Boolean = false;

                private var target:InteractiveObject;
                private var stage:Sprite;

                private var blurX:Number;
                private var blurY:Number;

                public function Drop(target:InteractiveObject,stage:Sprite) {

                        this.target = target;
                        this.stage = stage;

                        target.addEventListener(MouseEvent.MOUSE_DOWN,downHander);
                        target.addEventListener(MouseEvent.MOUSE_UP,upHander);
                        target.addEventListener(MouseEvent.MOUSE_MOVE,MoveHander);
                        //target.addEventListener(MouseEvent.MOUSE_OUT,OutHander);
                        target.addEventListener(Event.ENTER_FRAME,EnterFrameHander);
                }
                private function downHander(event:MouseEvent):void {

                        can = true;
                        grav = .6;
                        loop = 1;

                        trace("down");
                }
                private function upHander(event:MouseEvent):void {

                        can = false;
                        trace("UP");
                }
                private function MoveHander(event:MouseEvent):void {
                        if (can) {
                                grav = .1;

                                move();
                        }
                }
                private function OutHander(event:MouseEvent):void {

                        can = false;

                }
                private function EnterFrameHander(event:Event):void {
                        if (can) {
                                move();
                        } else {
                                target.filters = null;
                        }
                }
                private function move():void {
                        trace("move");

                        target.x += grav*(stage.mouseX - target.x)/loop;
                        target.y += grav*(stage.mouseY - target.y)/loop;

                        var filter:DropShadowFilter = new DropShadowFilter(10,45,0x666666,.6,blurX,blurY,1,3,false,false,false);
                        filter.blurX = filter.blurY = Math.abs((target.x-stage.mouseX)/3);
                        filter.distance = (target.x - stage.mouseX)/5;
                        target.filters = [filter];

                }
        }
}