UIPageViewController 上的 BAD_ACCESS

Question

我有一个工作中的

UIPageViewController

，其中嵌入了多个

UIViewControllers

，每个

UINavigationController

都有一个图像数组的预览，当打开时，会实例化一个新的

UIViewController

来显示这些图像当我滑动图像，然后滑动回第一个图像时，我的应用程序崩溃并显示“

UIPageViewController

”，当我使用

EXC_BAD_ACCESS(code=EXC_I386_GPFLT)

 的后退按钮时，同样的情况

这是为什么？我该如何解决这个问题？

我的 PageViewController（标记的行是我在调试器崩溃之前进入的最后一行）：

UINavigationController

所以结构看起来像这样

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()
    }
}

->

UINavigationController

->

DetailPageMasterViewController

->

DetailMinionViewController

->

PicturesPageMasterViewController

Answer 1

长话短说：

PicturesMinionViewController
中的

gestureRecognizer

尝试访问已经取消初始化的

PicturesMinionViewController

，我的

ImageView

工作正常

Answer 2