How can I make the transition of the UIPageViewController delegate computer to Swift?

Question

As you can see, there are two UIViewControllers(one of them is called ProViewand acts as a container for the other UIViewControllerand one UIPageViewController.

import UIKit

class ProView: UIViewController, UIPageViewControllerDataSource, UIPageViewControllerDelegate {

var pageViewController: UIPageViewController?

let characterImages = ["character1", "character2"]

override func viewDidLoad() {
    super.viewDidLoad()
    createPageViewController()
    setupPageControl()
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}

func pageViewController(pageViewController: UIPageViewController,
    viewControllerAfterViewController ProView: UIViewController) -> UIViewController? {

        let itemController = ProView as PageItemController

        if itemController.itemIndex+1 < characterImages.count {
            return getItemController(itemController.itemIndex+1)
        }

        return nil
}

func pageViewController(pageViewController: UIPageViewController,
    viewControllerBeforeViewController ProView: UIViewController) -> UIViewController? {

    let itemController = ProView as PageItemController

        if itemController.itemIndex > 0 {
            return getItemController(itemController.itemIndex-1)
        }

        return nil
}

private func getItemController(itemIndex: Int) -> PageItemController? {

    if itemIndex < characterImages.count {
        let pageItemController = self.storyboard!.instantiateViewControllerWithIdentifier("ItemController") as PageItemController
        pageItemController.itemIndex = itemIndex
        pageItemController.imageName = characterImages[itemIndex]
        return pageItemController
}

    return nil
}

func createPageViewController() {

    let pageController = self.storyboard!.instantiateViewControllerWithIdentifier("PageController") as UIPageViewController
    pageController.dataSource = self

    if characterImages.count > 0 {
        let firstController = getItemController(0)!
        let startingViewControllers: NSArray = [firstController]
        pageController.setViewControllers(startingViewControllers, direction:     UIPageViewControllerNavigationDirection.Forward, animated: false, completion: nil)
    }

    pageViewController = pageController
    addChildViewController(pageViewController!)
    self.view.addSubview(pageViewController!.view)
    pageViewController?.didMoveToParentViewController(self)
}

func setupPageControl() {
    let appearance = UIPageControl.appearance()
    appearance.pageIndicatorTintColor = UIColor.grayColor()
    appearance.currentPageIndicatorTintColor = UIColor.whiteColor()
}

func presentationCountForPageViewController(pageViewController: UIPageViewController) -> Int {
    return characterImages.count
}

func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int {
    return 0
}

}

class PageItemController: UIViewController {

@IBOutlet weak var imageCharacterChoose: UIImageView!

var itemIndex: Int = 0
var imageName: String = "" {
    didSet {

        if let imageView = imageCharacterChoose {imageCharacterChoose.image = UIImage(named: imageName)
        }

    }
}

override func viewDidLoad() {
    super.viewDidLoad()

    imageCharacterChoose!.image = UIImage(named: imageName)

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}

}

I would like to know if the user is viewing data from one view to another correctly. In this regard, I need a method transitionCompletedto work:

func pageViewController(ProView: UIPageViewController,
    didFinishAnimating finished: Bool,
    previousViewControllers pageViewController: [AnyObject],
    transitionCompleted completed: Bool)
{
// If the page did not turn
if (!completed)
{
// You do nothing because whatever page you thought
// the book was on before the gesture started is still the correct page
println("The page number did not change.")
return;
}

// This is where you would know the page number changed and handle it appropriately
println("The page number has changed.")
}

The problem is that it does not work (output to the console does not print anything), because the parameters are probably incorrect. According to the Apple Reference,

pageViewController The pageview controller. previousViewControllers View controllers before transition.

"ProView" "pageViewController", . transitionCompleted? - ?

Answer 1

, pageViewController:didFinishAnimating:... , .

:

pageController.dataSource = self

, dataSource. delegate. :

pageController.delegate = self