iOS11之前和iOS11之后是不一樣的

  if (@available(iOS 8.0, *))]
  {
   if (@available(iOS 11.0, *)){
        for (UIView* subview in wkWebView.scrollView.subviews) {
            if ([subview isKindOfClass:NSClassFromString(@"WKContentView")])
            {
                for (UIGestureRecognizer* longPress in subview.gestureRecognizers) {
                    if ([longPress isKindOfClass:UILongPressGestureRecognizer.class]) {
                        [subview removeGestureRecognizer:longPress];
                        return;
                    }
                }
            }
        }
    }

      for (UIView* subview in wkWebView.scrollView.subviews) {
        if ([subview isKindOfClass:NSClassFromString(@"WKContentViewMinusAccessoryView")])
        {
            for (UIGestureRecognizer* longPress in subview.gestureRecognizers) {
                if ([longPress isKindOfClass:UILongPressGestureRecognizer.class]) {
                    [subview removeGestureRecognizer:longPress];
                }
            }
        }
    }
}