通过tag 获得动作的api怎么用？

            var peopleSinger = this.node.children;
            var actionMovePeople = cc.moveTo(3, cc.p(0, 0));
            actionMovePeople.setTag(1);
            peopleSinger[i].runAction(actionMovePeople);
            var as2 = peopleSinger[i].getActionByTag(1);
            cc.log('as2' + as2);

按理来说 as2 应该可以获得的。但是运行后as2 显示undefined.