IOS上使用 mui('#pullrefresh').pullRefresh().scrollTo(0,0,2000)；报错

IOS上使用 mui('#pullrefresh').pullRefresh().scrollTo(0,0,2000)；出现 Cannot read property 'scrollTo' of undefined 报错，哪位大神，能告诉下怎么解决啊，百度无果啊