Assertion failure in UIQueuingScrollView didScrollWithAnimation:force:

Question

I\'ve got a UIPageViewController set up paging my ImageViewController.

The ImageViewController contains a UIScrollView

Answer 1

I had a similar problem. My setup was a UIPageViewController and I was loading view controllers with an UIImageView inside. When interacting while the UIPageViewController was scrolling I got the same crash log.

I fixed it by creating a UILongPressGestureRecognizer and add to the UIPageViewController's scroll view.

1. Created my own subclass of UIPageViewController (Solution is specific for my case but can easily used as a generic solution)

2. Find the inner UIScrollView of the UIPageViewController

   - (UIScrollView *)findScrollView
   {
       UIScrollView *scrollView;
       for (id subview in self.view.subviews)
       {
           if ([subview isKindOfClass:UIScrollView.class])
           {
               scrollView = subview;
               break;
           }
       }
   
       return scrollView;
   }
   

3. Add the long tap gesture recognizer to the inner scroll view and point its action to a method or nil

   /**
    *  On tap-hold the page view controller crashes as soon as it pages to a new view controller.
    *  Setting a long press gesture to ignore the hold.
    */
   - (void)listenForLongPressGestureOnScrollView:(UIScrollView *)scrollView
   {
       UILongPressGestureRecognizer *longPressGestureRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:nil];
       [longPressGestureRecognizer setMinimumPressDuration:0.5];
       [scrollView addGestureRecognizer:longPressGestureRecognizer];
   }