问如何在swift中重置/重新加载UI页面控制器视图

EN

//-----PAGE VC CODE------
import UIKit
import Firebase

protocol ProductImagesPageVCDelegate: class
{
    func setupPageController(numberOfPages: Int)
    func turnPageController(to index: Int)
}

class ProductImagesPageVC: UIPageViewController {

    var product: Product!

    weak var pageViewControllerDelegate: ProductImagesPageVCDelegate?

    struct StoryBoard {
        static let productImageVC = "ProductImageVC"
    }

    lazy var controllers: [UIViewController] = {

        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        var controllers = [UIViewController]()

        if let imageLinks = self.product.imageLinks
        {
            for imageLink in imageLinks
            {
                let productImageVC = storyboard.instantiateViewController(withIdentifier: StoryBoard.productImageVC)
                controllers.append(productImageVC)
            }
        }

        self.pageViewControllerDelegate?.setupPageController(numberOfPages: controllers.count)

        return controllers
    }()

    override func viewDidLoad() {
        super.viewDidLoad()

//        if #available(iOS 11.0, *) {
//            contentInsetAdjustmentBehavior = .never
//        } else {
//            automaticallyAdjustsScrollViewInsets = false
//        }
        automaticallyAdjustsScrollViewInsets = false
        dataSource = self
        delegate = self

        self.turnToPage(index: 0)


    }


    func turnToPage(index: Int)
    {
        let controller = controllers[index]
        var direction = UIPageViewControllerNavigationDirection.forward

        if let currentVC = viewControllers?.first
        {
            guard let currentIndex = controllers.index(of: currentVC) else {return}
            if currentIndex > index
            {
                direction = .reverse
            }
        }

        self.configuewDisplaying(viewController: controller)

        setViewControllers([controller], direction: direction, animated: true, completion: nil)

    }

    func configuewDisplaying(viewController: UIViewController)
    {
        for (index, vc) in controllers.enumerated()
        {
            if viewController === vc {
                if let productImageVC = viewController as? ProductImageVC
                {
                    productImageVC.imageLink = self.product.imageLinks?[index]

                    self.pageViewControllerDelegate?.turnPageController(to: index)
                }
            }
        }
    }


}

extension ProductImagesPageVC: UIPageViewControllerDataSource
{
    func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {

        if let index = controllers.index(of: viewController)
        {
            if index < controllers.count - 1
            {
                return controllers[index + 1]
            }
        }


        return controllers.first
    }

    func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {

        if let index = controllers.index(of: viewController)
        {
            if index > 0
            {
                return controllers[index - 1]
            }
        }

        return controllers.last
    }
}

extension ProductImagesPageVC: UIPageViewControllerDelegate
{

    func pageViewController(_ pageViewController: UIPageViewController, willTransitionTo pendingViewControllers: [UIViewController]) {

        self.configuewDisplaying(viewController: pendingViewControllers.first as! ProductImageVC)
    }

    func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {

        if !completed
        {
            self.configuewDisplaying(viewController: previousViewControllers.first as! ProductImageVC)
        }
    }



}