Question

我在UIPageViewController中有四个页面，我想隐藏最后一页上的点。我成功地创建了一个在UIPageViewController的最后一页调用的函数。基本上，如果当前视图是最后一个视图，则调用它。但是，我该用什么功能来暂时隐藏这些点？

我发现了这个https://stackoverflow.com/a/32016614/5700898，但它对该功能内部的内容没有帮助。正常方法（隐藏所有页面上的页面点）不是我需要的。

如何仅在UIPageViewController的最后一页上隐藏页面指示符点？

修改：这是我要求的代码。

import UIKit

class TutorialController: UIPageViewController {

    let pageControl = UIPageControl.appearanceWhenContainedInInstancesOfClasses([])

    var currentview = "0"

    private func stylePageControl() {

        pageControl.currentPageIndicatorTintColor = UIColor.lightGrayColor()
        pageControl.pageIndicatorTintColor = UIColor.darkGrayColor()
        pageControl.backgroundColor = UIColor.whiteColor()
    }

    private func hidePageControl() { // this should let us hide the dots on the fourth view, by changing color.

        pageControl.backgroundColor = UIColor(red: 0.2980392157, green: 0.2980392157, blue: 0.2980392157, alpha: 1.0)
        pageControl.currentPageIndicatorTintColor = UIColor(red: 0.2980392157, green: 0.2980392157, blue: 0.2980392157, alpha: 1.0)
        pageControl.pageIndicatorTintColor = UIColor(red: 0.2980392157, green: 0.2980392157, blue: 0.2980392157, alpha: 1.0)
    }


    private(set) lazy var orderedViewControllers: [UIViewController] = {
        return [self.newViewController("1"),
                self.newViewController("2"),
                self.newViewController("3"),
                self.newViewController("4")]
    }()

    private func newViewController(number: String) -> UIViewController {
        return UIStoryboard(name: "Main", bundle: nil) .
            instantiateViewControllerWithIdentifier("Tutorial\(number)") // calls the next view controller.
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        stylePageControl() // just changing the color, this works.
        dataSource = self

        if let firstViewController = orderedViewControllers.first {
            setViewControllers([firstViewController],
                               direction: .Forward,
                               animated: true,
                               completion: nil)
        }

    }
}

// MARK: UIPageViewControllerDataSource

extension TutorialController: UIPageViewControllerDataSource {

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

    }

    func presentationIndexForPageViewController(pageViewController: UIPageViewController) -> Int {
        guard let firstViewController = viewControllers?.first,
            firstViewControllerIndex = orderedViewControllers.indexOf(firstViewController) else {
                return 0
        }

        return firstViewControllerIndex
    }


    func pageViewController(pageViewController: UIPageViewController,
                            viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {
        guard let viewControllerIndex = orderedViewControllers.indexOf(viewController) else {
            return nil
        }

        let previousIndex = viewControllerIndex - 1


        guard previousIndex >= 0 else {
            return nil
        }

        guard orderedViewControllers.count > previousIndex else {
            return nil
        }

        return orderedViewControllers[previousIndex]
    }

    func pageViewController(pageViewController: UIPageViewController,
                            viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {
        guard let viewControllerIndex = orderedViewControllers.indexOf(viewController) else {
            return nil
        }

        let nextIndex = viewControllerIndex + 1
        currentview = "\(nextIndex)"
        print("now on tutorial slide \(currentview)")
        if currentview == "4" { // this is called successfully when the fourth page comes into view.
            print("we are now on the fourth slide; hiding the page dots...") // this successfully prints.


      UIPageControl.appearanceWhenContainedInInstancesOfClasses([TutorialController.s‌elf]).hidden = true // this should hide the all page controller dots, but it just doesn't work.
        pageControl.hidden = true // also should hide page controller dots, also doesn't work.
        hidePageControl() // this should change the color of the page controller dots, but doesn't (note that this function works to change color when I call it on viewDidLoad, but that's not where I want it; it doesn't work here).

        print(pageControl.hidden) // always prints false, even though I am trying to set it to true.

        }

        let orderedViewControllersCount = orderedViewControllers.count

        guard orderedViewControllersCount != nextIndex else {
            return nil
        }

        guard orderedViewControllersCount > nextIndex else {
            return nil
        }

        return orderedViewControllers[nextIndex]
    }

}

Answer 1

使用UIPageViewControllerDelegate方法：

let pageControl = UIPageControl()

func pageViewController(pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
    if (index == numberOfPages()-1){
          pageControl.hidden = true
    }else{
          pageControl.hidden = false
    }
}

Answer 2

我发现你实际上无法隐藏页面控件，因为它永远不会起作用。但有点黑客就是将其添加到您的代码中：

    func pageViewController(pageViewController: UIPageViewController, willTransitionToViewControllers pendingViewControllers: [UIViewController]) {
        if let lastVC = pendingViewControllers.last?.isKindOfClass(youLastViewController){
            if lastVC == true {
                for view in self.view.subviews {
                    if view is UIScrollView {
                        view.frame = UIScreen.mainScreen().bounds
                    } else if view is UIPageControl {
                        view.center.y = self.view.frame.height * 1.5
                    }
                }
            }else {
                for view in self.view.subviews {
                    if view is UIScrollView {
                        view.frame = UIScreen.mainScreen().bounds
                    } else if view is UIPageControl {
                        view.center.y = self.view.frame.height * 0.92
                    }
                }
            }
        }
    }
}

这实际上会移动屏幕的页面控件，就像隐藏它一样。

Answer 3

这里是UIPageViewController的完整代码，用于隐藏最后一页的点，它工作正常

首先为UIViewController创建类并添加UIPageViewControllerDelegate，UIPageViewControllerDataSource

为pageControl创建插座

@IBOutlet weak var pageControl：UIPageControl！

为uipagecontroller创建变量

- some_meth(blog( ENV[ "site" ] ).articles.select { | a | a.data[ :category ] == category }, 'all')

ViewDidLoad中的

：添加以下行：

var pageControllerContainer : UIPageViewController!

var pages = [UIViewController]()

var currentIndex : Int?

private var pendingIndex : Int?
private var lastIndex : Int?

现在为pageviewcontroller创建以下委托方法：

 let page1 : UIViewController! = self.storyboard?.instantiateViewController(withIdentifier: "YourFirstPageViewController") as! YourFirstPageViewController
    let page2 : UIViewController! = self.storyboard?.instantiateViewController(withIdentifier: "YourSecondPageViewController") as! YourSecondPageViewController
    let page3 : UIViewController! = self.storyboard?.instantiateViewController(withIdentifier: "YourThirdPageViewController") as! YourThirdPageViewController

    pages.append(page1)
    pages.append(page2)
    pages.append(page3)

    pageControllerContainer = UIPageViewController(transitionStyle: .scroll, navigationOrientation: .horizontal, options: nil)
    pageControllerContainer.delegate = self
    pageControllerContainer.dataSource = self
    pageControllerContainer.setViewControllers([page1], direction: .forward, animated: true, completion: nil)

    view.addSubview(pageControllerContainer.view)
    view.bringSubview(toFront: pageControl)
    pageControl.numberOfPages = pages.count
    pageControl.currentPage = 0

之后创建以下数据源方法

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

    let currentIndex = pages.index(of: viewController)

    if currentIndex == 0
    {
        return nil
    }
    let previousIndex = abs((currentIndex! - 1) % pages.count)
    return pages[previousIndex]
}

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


    let currentIndex = pages.index(of: viewController)

    if currentIndex == pages.count - 1
    {
        return nil
    }

    let nextIndex = abs((currentIndex! + 1 ) % pages.count)
    return pages[nextIndex]
}

这将允许隐藏页面控制器，当涉及到最后一个索引意味着最后一页

希望这会有所帮助:-)谢谢你......

Answer 4

在这里查看接受的答案以获取UIPageControl（带点的视图）：

Access the UIPageControl created by iOS6 UIPageViewController?

然后，一旦你有了pageControl，你可以在pageViewController: didFinishAnimating:中查看它是否是最后一页，如果是，请设置pageControl.hidden = true。

Answer 5

override func presentationCountForPageViewController(pageViewController: UIPageViewController) -> Int {
    if /*current index is the last one*/ {
        return 0
    } else {
        /*return number of pages*/
    }
}

在UIPageViewController swift的最后一页上隐藏点

5 个答案: