ios - Swift:UIPageViewController - 加载单独的 View

Question

我正在学习本教程:http://swiftiostutorials.com/ios-tutorial-using-uipageviewcontroller-create-content-slider-objective-cswift/创建一个显示多个 slider 的应用程序。

尽管我已经让本教程发挥作用，但此示例仅根据存储在数组中的图像更改图像。

如何让它加载 ViewController 而不是图像

我有 4 个 View Controller :

• ViewController1
• ViewController2
• ViewController3
• ViewController4

我想在第一张幻灯片中显示 ViewController1，在第二张幻灯片中加载 ViewController2 等....

这是我的主视图 Controller :

 import UIKit

class ViewController: UIViewController, UIPageViewControllerDataSource {

// MARK: - Variables
private var pageViewController: UIPageViewController?

// Initialize it right away here
private let contentImages = ["nature_pic_1.png",
                             "nature_pic_2.png",
                             "nature_pic_3.png",
                             "nature_pic_4.png"];

// MARK: - View Lifecycle
override func viewDidLoad() {
    super.viewDidLoad()
    createPageViewController()
    setupPageControl()
}

private func createPageViewController() {

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

    if contentImages.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)
}

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

// MARK: - UIPageViewControllerDataSource

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

    let itemController = viewController as PageItemController

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

    return nil
}

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

    let itemController = viewController as PageItemController

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

    return nil
}

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

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

    return nil
}

// MARK: - Page Indicator

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

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

这是我的 PageItemController:

import UIKit

class PageItemController: UIViewController {

// MARK: - Variables
var itemIndex: Int = 0
var imageName: String = "" {

    didSet {

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

    }
}

@IBOutlet var contentImageView: UIImageView?

// MARK: - View Lifecycle
override func viewDidLoad() {
    super.viewDidLoad()
    contentImageView!.image = UIImage(named: imageName)
}
}

我是 Swift/iOS 开发的新手，我真的很想通过开发来融入其中。预先感谢您的回答:)

编辑:使问题清晰

如何使 View Controller 数组对应于 UIPageViewController 的左/右滑动？

因此，当我在 ViewController1 上向左滑动时 - 加载 UIViewController2 并反向向右滑动。

Answer 1

假设您在与 UIPageViewController 相同的 Storyboard中定义了 View Controller 1-4，并且您将它们的 Storyboard ID 设置为 ViewController0、ViewController1 等等，然后创建一个方法来填充 View Controller 数组并在你的 viewDidLoad() 在调用 createPageViewController()

之前

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

像这样实现方法:

    var controllers = [PageItemController]()

    func populateControllersArray() {
        for i in 0...3 {
            let controller = storyboard!.instantiateViewControllerWithIdentifier("ViewController\(i)") as PageItemController
            controller.itemIndex = i
            controllers.append(controller)
        }
    }

然后定义你的 createPageViewController() 如下

    private func createPageViewController() {

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

        if !controllers.isEmpty {
            pageController.setViewControllers([controllers[0]], direction: UIPageViewControllerNavigationDirection.Forward, animated: false, completion: nil)
        }

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

然后在你的两个委托(delegate)之前和之后的方法中:

    func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {
        if let controller = viewController as? PageItemController {
            if controller.itemIndex > 0 {
                return controllers[controller.itemIndex - 1]
            }
        }
        return nil
    }
    func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {
        if let controller = viewController as? PageItemController {
            if controller.itemIndex < controllers.count - 1 {
                return controllers[controller.itemIndex + 1]
            }
        }
        return nil
    }

并在计数方法中

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

---

事实上，您可以使用您想要显示的任何 View Controller 填充controllers，只需在 Storyboard中将它们的类设置为PageItemController(以便具有索引属性)。

或者您可以将每个 View Controller 设置为它自己的类，并使用运行时属性获取和设置。

在 before 和 after 方法中使用 controller.valueForKey("itemIndex") as Int 而不是 controller.itemIndex

在 populateControllersArray() 中使用 controller.setValue(i, forKey: "itemIndex") 而不是 controller.itemIndex = i。

只需确保每个 Controller 类都具有 Int 属性 itemIndex，否则您的应用程序将崩溃。

要将所有内容整合到您的代码中，请执行以下操作:

import UIKit

import UIKit

class ViewController: UIViewController, UIPageViewControllerDataSource {

    // MARK: - Variables
    private var pageViewController: UIPageViewController?

    // MARK: - View Lifecycle
    override func viewDidLoad() {
        super.viewDidLoad()
        populateControllersArray()
        createPageViewController()
        setupPageControl()
    }

    var controllers = [PageItemController]()


    func populateControllersArray() {
        for i in 0...3 {
            let controller = storyboard!.instantiateViewControllerWithIdentifier("ViewController\(i)") as PageItemController
            controller.itemIndex = i
            controllers.append(controller)
        }
    }

    private func createPageViewController() {

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

        if !controllers.isEmpty {
            pageController.setViewControllers([controllers[0]], direction: UIPageViewControllerNavigationDirection.Forward, animated: false, completion: nil)
        }

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

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

    // MARK: - UIPageViewControllerDataSource
    func pageViewController(pageViewController: UIPageViewController, viewControllerBeforeViewController viewController: UIViewController) -> UIViewController? {
        if let controller = viewController as? PageItemController {
            if controller.itemIndex > 0 {
                return controllers[controller.itemIndex - 1]
            }
        }
        return nil
    }
    func pageViewController(pageViewController: UIPageViewController, viewControllerAfterViewController viewController: UIViewController) -> UIViewController? {
        if let controller = viewController as? PageItemController {
            if controller.itemIndex < controllers.count - 1 {
                return controllers[controller.itemIndex + 1]
            }
        }
        return nil
    }

    // MARK: - Page Indicator

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

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