如果允许垂直滚动，Foxit不稳定

Question

有人知道为什么Foxit在限制垂直滚动时会变慢并崩溃吗？

- (void)onPageChanged:(int)oldIndex currentIndex:(int)currentIndex;
{
    if (pdfViewLastOpened.subviews.count > 0) {
        UIView *v = pdfViewLastOpened.subviews[0];
        if (v.subviews.count > 0) {
            UIView *v2 = v.subviews[0];
            for (UIView *v3 in v2.subviews) {
                if ([v3 isKindOfClass:[UIScrollView class]]) {
                    UIScrollView *v4 = (UIScrollView *)v3;
                    [v4.panGestureRecognizer requireGestureRecognizerToFail:self.tableView.panGestureRecognizer];
                }
            }
        }
    }
}