PageViewController current page index in Swift

Question

I want to get current index of a pageViewController, I don\'t know how I get the visible pages index.

func pageViewController(pageViewController: UIPageViewContr         


        

Answer 1

Use viewDidAppear that mark page as visible and viewDidDisappear that mark page as invisible

Item ViewController:

class PageItemViewController: UIViewController {

    private(set) var isVisible: Bool = false

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        isVisible = true
    }

    override func viewDidDisappear(_ animated: Bool) {
        super.viewDidDisappear(animated)
        isVisible = false
    }   
}

Get index of the visible page

class PageViewController: UIPageViewController, UIPageViewControllerDelegate {

    var items: [PageItemViewController] = [] {
        didSet {
            if let last = items.last {
                setViewControllers([last], direction: .forward, animated: true, completion: nil)
            }
        }
    }

    // ...

    public func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
        if finished {
            guard let currentIndex = items.firstIndex(where: { $0.isVisible }) else { return }
            print(currentIndex)
        }
    }
}