//以下三行为不生效代码,clear()没有能够清除这个节点的纹理
(this.owner as Laya.Sprite).graphics.clear();
var t: Laya.Texture = Laya.loader.getRes("puzzlePic/pi-" +this.levelNum +"-"+this.owner.name.slice(4,1)+ "-2.png");
(this.owner as Laya.Sprite).graphics.drawTexture(t,0,0);