http://mp.weixin.qq.com/s?__biz=MzAwODM1NjIwOQ==&mid=503718283&idx=1&sn=fd72cf0477ee4567a5f8650c46c8fb36&chksm=0082a99537f5208315bda84b7450df0b78ea17776ed6941227b2212c76fe836363b4bfeca343&mpshare=1&scene=2&srcid=1013UwPR3xBKTElJK4c3QeIy&from=timeline&isappinstalled=0#wechat_redirect
链接里还有补救的方法 希望能帮到你