UIScrollView横向滑动,pan手势跟系统的返回手势冲突解决方法

self.scrollView.panGestureRecognizer.requireGestureRecognizerToFail(navigationController!.interactivePopGestureRecognizer!)

swift:

   if let ges = self.navigationController?.interactivePopGestureRecognizer {
            pan.require(toFail: ges)
        }