如何拥有一个多页的页面视图控制器，但在 swift 4 中只使用一个视图控制器？

Question

我有一个运行良好的页面视图控制器 - 我想要一个视图控制器但是在页面视图控制器中有多个页面 - 我的意思是当用户滚动可以再次看到该视图控制器并且在情节提要中只有一个视图控制器这是我的代码，但当我想将页数更改为多于一页时，它无法正常工作这是我的代码

class mainPage:  UIPageViewController, UIPageViewControllerDataSource , UIPageViewControllerDelegate {


    let pageVC3 = UIPageControl()
    lazy var VCArr : [UIViewController] = {

        return [self.VCInstance(name : "page")]

    }()

    private func VCInstance(name : String) -> UIViewController {

        return UIStoryboard(name : "Main" , bundle : nil).instantiateViewController(withIdentifier: name)


    }


    override func viewDidLoad() {
        super.viewDidLoad()

        let pageControl = UIPageControl.appearance()

        pageControl.layer.position.y = self.view.frame.height - 20

        pageControl.pageIndicatorTintColor = UIColor.init(red: 255/255, green: 255/255, blue: 255/255, alpha: 0.3)

        pageControl.currentPageIndicatorTintColor = UIColor.init(red: 255/255, green: 255/255, blue: 255/255, alpha: 0.6)

        //Setting the background of the view controller so the dots wont be on a black background

        self.view.backgroundColor = UIColor.black
        self.dataSource = self
        self.delegate = self
        if let firstVC = VCArr.first {

            setViewControllers([firstVC] , direction: .forward , animated: true, completion: nil)
            setViewControllers([firstVC] , direction: .reverse , animated: true, completion: nil)

        }

    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        for subV in self.view.subviews {
            if type(of: subV).description() == "UIPageControl" {

                let pos = CGPoint(x: 0, y: 600)
                subV.frame = CGRect(origin: pos, size: subV.frame.size)

            }
        }

        for view in self.view.subviews {
            if view is UIScrollView {
                view.frame = UIScreen.main.bounds
            }else if view is UIPageControl{
                view.backgroundColor = UIColor.clear

            }
        }
    }



    public func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController?{
        guard let viewControllerIndex = VCArr.index(of: viewController) else {
            return nil

        }

        let previousIndex = viewControllerIndex-1
        guard previousIndex >= 0  else {
            return nil

        }

        guard VCArr.count > previousIndex else {
            return nil
        }

        return VCArr[previousIndex]
    }

    public func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController?{
        guard let viewControllerIndex = VCArr.index(of: viewController) else {
            return nil
        }

        let nextIndex = viewControllerIndex+1
        guard nextIndex < VCArr.count
            else {
                return nil
        }

        guard VCArr.count > nextIndex else {
            return nil
        }

        return VCArr[nextIndex]
    }





    public func presentationCount(for pageViewController: UIPageViewController) -> Int{
        return 3
    }


    public func presentationIndex(for pageViewController: UIPageViewController) -> Int{
        guard let firstViewController = viewControllers?.first , let firstViewControllerIndex = VCArr.index(of: firstViewController) else {
            return 0
        }


        return firstViewControllerIndex
    }


  }

Answer 1

问题出在这段代码中

if let firstVC = VCArr.first {

        setViewControllers([firstVC] , direction: .forward , animated: true, completion: nil)
        setViewControllers([firstVC] , direction: .reverse , animated: true, completion: nil)

    }

您在 pageController 中添加了相同的对象。

尝试创建不同的对象并添加到 pageviewcontroller

let  item1 = ViewControler()
let item 2 = ViewControler()

在 PageController 中添加这两个对象

Answer 2

所以这是我找到的答案

我不得不使用这个

 lazy var VCArr : [UIViewController] = {

        return []

    }()

然后使用这个

 var numberOfPages = 3

    override func viewDidLoad() {
        super.viewDidLoad()


        for _ in 0...numberOfPages - 1 {
            VCArr.append(self.VCInstance(name : "page"))                
        }
   }

因此，正如您所见，页面视图控制器页面可以根据页面数进行更改

如何拥有一个多页的页面视图控制器，但在 swift 4 中只使用一个视图控制器？

how to have a page view controller with more than one page But using just one view controller in swift 4?

ios

swift4

viewcontroller

uipageviewcontroller