Question

我有一个uipageviewcontroller，里面有四个独立的视图控制器。我想为第一个视图控制器禁用右滑动操作，并禁用第四个视图控制器的左滑动操作。当应用程序启动时，我希望用户只能向左滑动而不是向右滑动，因为向右滑动，将用户带到第四个视图控制器并在第四个视图控制器上向左滑动将用户带到第一个视图控制器。这是我的代码。

class TutorialPageViewController: UIPageViewController, UIPageViewControllerDataSource, UIPageViewControllerDelegate {
    weak var tutorialDelegate: TutorialPageViewControllerDelegate?

    lazy var VCArr: [UIViewController] = {
        return [self.VCInstance(name: "FirstVC"),
                self.VCInstance(name: "SecondVC"),
                self.VCInstance(name: "ThirdVC"),
                self.VCInstance(name: "FourthVC")]

    }()

    private func VCInstance(name: String) -> UIViewController {
        return UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: name)
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        let pageControl = UIPageControl.appearance()
        //Customizing
        pageControl.pageIndicatorTintColor = UIColor.lightGray
        pageControl.currentPageIndicatorTintColor = UIColor(red:0.23, green:0.73, blue:1.00, alpha:1.0)

        dataSource = self
        delegate = self
        self.dataSource = self
        self.delegate = self

        if let FirstVC = VCArr.first {
            setViewControllers([FirstVC], direction: .forward, animated: true, completion: nil)
            tutorialDelegate?.tutorialPageViewController(tutorialPageViewController: self, didUpdatePageCount: VCArr.count)

        }
    }

   override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()

        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 VCArr.last
        }

        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 VCArr.first
        }

        guard VCArr.count > nextIndex else {
            return nil
        }
        return VCArr[nextIndex]
    }

    public func presentationCount(for pageViewController: UIPageViewController) -> Int {
        return VCArr.count
    }


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

extension TutorialPageViewController {

    func pageViewController(pageViewController: UIPageViewController,
                            didFinishAnimating finished: Bool,
                            previousViewControllers: [UIViewController],
                            transitionCompleted completed: Bool) {
        if let firstViewController = viewControllers?.first,
            let index = VCArr.index(of: firstViewController) {
            tutorialDelegate?.tutorialPageViewController(tutorialPageViewController: self, didUpdatePageIndex: index)
        }
    }

}

Answer 1

基本上你需要改变以下几行

guard previousIndex >= 0 else {
            return nil
        }


guard nextIndex < VCArr.count else {
            return nil
        }

-----或-----

将viewControllerAfter更改为

 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]
        }

将ViewController更改为

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]
    }

Answer 2

您可以使用此扩展名禁用所有方向的滑动：

extension UIPageViewController {
     var isPagingEnabled: Bool {
        get {
           var isEnabled: Bool = true
           for view in view.subviews {
               if let subView = view as? UIScrollView {
                   isEnabled = subView.isScrollEnabled
               }
           }
           return isEnabled
       }
       set {
           for view in view.subviews {
               if let subView = view as? UIScrollView {
                   subView.isScrollEnabled = newValue
               }
           }
       }
   }    
}

并称呼它：

pageCtrl.isPagingEnabled = false

uipageviewcontroller禁用右键滑动

2 个答案: