AS 3缓动类Tween类的初次使用

import flash.display.Sprite;
import fl.transitions.Tween;
import fl.transitions.easing.*;

stage.frameRate=30;
//画个实心球
var canvas:Sprite=new Sprite();
canvas.graphics.beginFill(0);
canvas.graphics.drawCircle(20,40,10);
canvas.graphics.endFill();
stage.addChild(canvas);
//体验tween类动作效果，可以换成Back，Bounce或者None等等
var t:Tween=new Tween(canvas,"y",Elastic.easeOut,0,300,20,true);