BAD_ACCESS on UIPageViewController - ios

Question

I've got a working UIPageViewController that holds multiple UIViewControllers embedded in an UINavigationController and each UIViewController has a preview of an array of images wich, when opened, instantiate a new UIPageViewController to display those images
when i swipe through the images and then swipe back to the first one my app crashes with "EXC_BAD_ACCESS(code=EXC_I386_GPFLT)" same thing when i use the back button of the UINavigationController
why is that and how can i fix this ?
My PageViewController (the marked line is the last one i got in the debugger before it crashes):
class DetailPageMasterViewController: UIPageViewController, UIPageViewControllerDelegate, UIPageViewControllerDataSource
{
var presentationPageIndex: Int = 0
var itemsArray = [Aktion]()
var pageViewController: UIPageViewController!
#IBOutlet weak var btnEditOutlet: UIBarButtonItem!
#IBAction func btnEditAction(sender: AnyObject)
{
}
override func viewDidLoad()
{
super.viewDidLoad()
self.pageViewController = UIPageViewController.init(transitionStyle: .Scroll,
navigationOrientation: .Horizontal,
options: nil)
self.pageViewController.delegate = self
self.pageViewController.dataSource = self
self.presentationPageIndex = 0
let firstVC = self.viewControllerAtIndex(presentationPageIndex)
let viewControllers = [firstVC]
self.pageViewController.setViewControllers(viewControllers,
direction: .Forward,
animated: false,
completion: nil)
self.addChildViewController(self.pageViewController)
self.view.addSubview(self.pageViewController.view)
self.pageViewController.didMoveToParentViewController(self)
self.setupPageControl()
}
func pageViewController(pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool)
{
if completed
{
let minionVC = self.pageViewController.viewControllers?.last as! DetailMinionViewController
presentationPageIndex = minionVC.pageIndex
}
}
func viewControllerAtIndex(index: Int) -> DetailMinionViewController
{
let contentVC = self.storyboard?.instantiateViewControllerWithIdentifier("MinionPageViewController") as! DetailMinionViewController
contentVC.aktion = itemsArray[index]
contentVC.pageIndex = index
return contentVC
}
func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController?
{
if let viewController = viewController as? DetailMinionViewController
{
var index = viewController.pageIndex
if index == 0 || index == NSNotFound
{
return nil //MARKED LINE
}
index -= 1
return self.viewControllerAtIndex(index)
}
return nil
}
func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController?
{
if let viewController = viewController as? DetailMinionViewController
{
var index = viewController.pageIndex
if index == NSNotFound
{
return nil
}
index += 1
if index == NSNotFound || index >= itemsArray.count
{
return nil
}
return self.viewControllerAtIndex(index)
}
return nil
}
func presentationCountForPageViewController(pageViewController: UIPageViewController) -> Int
{
return itemsArray.count
}
func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int
{
return presentationPageIndex
}
func setupPageControl()
{
UIPageControl.appearance().backgroundColor = UIColor.clearColor()
UIPageControl.appearance().pageIndicatorTintColor = UIColor.whiteColor()
UIPageControl.appearance().currentPageIndicatorTintColor = UIColor.redColor()
}
}
So the structure looks like
UINavigationController -> DetailPageMasterViewController -> DetailMinionViewController -> PicturesPageMasterViewController -> PicturesMinionViewController

Answer 1

So i finally figured out what caused my app to crash.
Long story short:
a gestureRecognizer in the PicturesMinionViewController tried to access an already deinitialized ImageView, my pageViewController worked fine

Answer 2

Please check the number of viewController added into the PageController. If possible you can share your code.