iPhoneX

1.在有底部tab時，界面自動佈局

[_subView mas_makeConstraints:^(MASConstraintMaker *make) {
            make.edges.equalTo(_subView.superview).with.insets(UIEdgeInsetsMake(0, 0, 0, 0));
        }];
        self.edgesForExtendedLayout = UIRectEdgeNone;//關鍵在於這一句