Question

当我在页面之间快速滑动时，有时会得到重复的页面。我的索引计数可能是错误的，但我尝试了一切，并始终得到相同。

DetailedProfileViewController.swift

class DetailedProfileViewController: UIViewController, UIPageViewControllerDataSource, UIPageViewControllerDelegate {

    var currentProfileIndex : Int?
    var nextProfileIndex :Int?
    var data: Main?

    var mainPageView : UIPageViewController!

    override func viewDidLoad() {
        super.viewDidLoad()

        let profile = ProfileViewController()
        profile.profile = currentProfile()
        let arraysOfViews = [profile]

        mainPageView = UIPageViewController(transitionStyle: .scroll, navigationOrientation: .horizontal, options: [:])
        mainPageView.setViewControllers(arraysOfViews, direction: .forward, animated: true, completion: nil)
        mainPageView.dataSource = self
        mainPageView.delegate = self

        addChildViewController(mainPageView)
        view.addSubview(mainPageView.view)
        mainPageView.didMove(toParentViewController: self)

    }

    func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
        if currentProfileIndex == (data?.filteredProfiles.count)!-1 { return nil }
        nextProfileIndex = abs((currentProfileIndex! + 1) % (data?.filteredProfiles.count)!)
        let profile = ProfileViewController()
        profile.profile = data?.filteredProfiles[nextProfileIndex!]
        return profile
    }

    func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
        if currentProfileIndex == 0 { return nil }
        nextProfileIndex = abs((currentProfileIndex! - 1) % (data?.filteredProfiles.count)!)
        let profile = ProfileViewController()
        profile.profile = data?.filteredProfiles[nextProfileIndex!]
        return profile
    }

    func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
        if completed == true {
          currentProfileIndex = nextProfileIndex
        }
    }
}

我没有在viewDidLoad中设置所有View Controller，因为它可能有数百个..

Answer 1

最愚蠢的解决方案是向index添加ProfileViewController。如果这样做，您可以将其设置为零到第一页。每当要求您提供下一个或上一个视图控制器时，您总是相对于哪个索引知道，因为您可以从给定的pageViewController（实际上是您的ProfileViewController）中提取它。

否则currentProfileIndex的处理可能非常容易出错。

<强>更新

class DetailedProfileViewController: UIViewController, UIPageViewControllerDataSource, UIPageViewControllerDelegate {

    var data: Main?

    var mainPageView : UIPageViewController!

    override func viewDidLoad() {
        super.viewDidLoad()

        let profile = ProfileViewController()
        profile.index = 0
        profile.profile = currentProfile()
        let arraysOfViews = [profile]

        mainPageView = UIPageViewController(transitionStyle: .scroll, navigationOrientation: .horizontal, options: [:])
        mainPageView.setViewControllers(arraysOfViews, direction: .forward, animated: true, completion: nil)
        mainPageView.dataSource = self
        mainPageView.delegate = self

        addChildViewController(mainPageView)
        view.addSubview(mainPageView.view)
        mainPageView.didMove(toParentViewController: self)

    }

    func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
        guard let pagesCount = data?.filteredProfiles.count else {
            return nil
        }

        guard let newIndex = (viewController as? ProfileViewController).index + 1, newIndex < pagesCount else {
            return nil
        }

        let profile = ProfileViewController()
        profile.profile = data?.filteredProfiles[newIndex]
        profile.index = newIndex
        return profile
    }

    func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
        guard let pagesCount = data?.filteredProfiles.count else {
            return nil
        }

        guard let newIndex = (viewController as? ProfileViewController).index - 1, newIndex >= 0 else {
            return nil
        }


        let profile = ProfileViewController()
        profile.profile = data?.filteredProfiles[newIndex!]
        profile.index = newIndex
        return profile
    }
}

带有动态DataSource页面的UIPageViewController会重复出现

1 个答案: