Question

我是Swift和app开发的新手，所以请耐心等待。我正在慢慢开发我的应用程序的UI，并且出于某种原因，当我去运行应用程序时，它显示第一个控制器上的背景图像与我指定的不同。

除此之外，我不确定如何解释它。对不起，如果这听起来令人困惑......我很困惑。

我还没有编写任何代码。我创建了应用程序，然后直接进入故事板，并在我进入代码并更改之前开始以我想要的方式制作它。

我的代码如下：

的AppDelegate

import UIKit

@UIApplicationMain class AppDelegate：UIResponder，UIApplicationDelegate {

var window: UIWindow?


func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.
    return true
}

func applicationWillResignActive(_ application: UIApplication) {
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
}

func applicationDidEnterBackground(_ application: UIApplication) {
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}

func applicationWillEnterForeground(_ application: UIApplication) {
    // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
}

func applicationDidBecomeActive(_ application: UIApplication) {
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}

func applicationWillTerminate(_ application: UIApplication) {
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}

}

RootViewController的

import UIKit

类RootViewController：UIViewController，UIPageViewControllerDelegate {

var pageViewController: UIPageViewController?


override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    // Configure the page view controller and add it as a child view controller.
    self.pageViewController = UIPageViewController(transitionStyle: .pageCurl, navigationOrientation: .horizontal, options: nil)
    self.pageViewController!.delegate = self

    let startingViewController: DataViewController = self.modelController.viewControllerAtIndex(0, storyboard: self.storyboard!)!
    let viewControllers = [startingViewController]
    self.pageViewController!.setViewControllers(viewControllers, direction: .forward, animated: false, completion: {done in })

    self.pageViewController!.dataSource = self.modelController

    self.addChildViewController(self.pageViewController!)
    self.view.addSubview(self.pageViewController!.view)

    // Set the page view controller's bounds using an inset rect so that self's view is visible around the edges of the pages.
    var pageViewRect = self.view.bounds
    if UIDevice.current.userInterfaceIdiom == .pad {
        pageViewRect = pageViewRect.insetBy(dx: 40.0, dy: 40.0)
    }
    self.pageViewController!.view.frame = pageViewRect

    self.pageViewController!.didMove(toParentViewController: self)
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

var modelController: ModelController {
    // Return the model controller object, creating it if necessary.
    // In more complex implementations, the model controller may be passed to the view controller.
    if _modelController == nil {
        _modelController = ModelController()
    }
    return _modelController!
}

var _modelController: ModelController? = nil

// MARK: - UIPageViewController delegate methods

func pageViewController(_ pageViewController: UIPageViewController, spineLocationFor orientation: UIInterfaceOrientation) -> UIPageViewControllerSpineLocation {
    if (orientation == .portrait) || (orientation == .portraitUpsideDown) || (UIDevice.current.userInterfaceIdiom == .phone) {
        // In portrait orientation or on iPhone: Set the spine position to "min" and the page view controller's view controllers array to contain just one view controller. Setting the spine position to 'UIPageViewControllerSpineLocationMid' in landscape orientation sets the doubleSided property to true, so set it to false here.
        let currentViewController = self.pageViewController!.viewControllers![0]
        let viewControllers = [currentViewController]
        self.pageViewController!.setViewControllers(viewControllers, direction: .forward, animated: true, completion: {done in })

        self.pageViewController!.isDoubleSided = false
        return .min
    }

    // In landscape orientation: Set set the spine location to "mid" and the page view controller's view controllers array to contain two view controllers. If the current page is even, set it to contain the current and next view controllers; if it is odd, set the array to contain the previous and current view controllers.
    let currentViewController = self.pageViewController!.viewControllers![0] as! DataViewController
    var viewControllers: [UIViewController]

    let indexOfCurrentViewController = self.modelController.indexOfViewController(currentViewController)
    if (indexOfCurrentViewController == 0) || (indexOfCurrentViewController % 2 == 0) {
        let nextViewController = self.modelController.pageViewController(self.pageViewController!, viewControllerAfter: currentViewController)
        viewControllers = [currentViewController, nextViewController!]
    } else {
        let previousViewController = self.modelController.pageViewController(self.pageViewController!, viewControllerBefore: currentViewController)
        viewControllers = [previousViewController!, currentViewController]
    }
    self.pageViewController!.setViewControllers(viewControllers, direction: .forward, animated: true, completion: {done in })

    return .mid
}

}

DataViewController 导入UIKit

class DataViewController：UIViewController {

@IBOutlet weak var dataLabel: UILabel!
var dataObject: String = ""


override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
}

}

ModelController

import UIKit

/ * 管理简单模型的控制器对象 - 月份名称的集合。

控制器作为页面视图控制器的数据源;因此它实现了pageViewController：viewControllerBeforeViewController：和pageViewController：viewControllerAfterViewController：。它还实现了一个自定义方法viewControllerAtIndex：它在数据源方法的实现和应用程序的初始配置中很有用。

不需要事先为每个页面实际创建视图控制器 - 实际上这样做会产生不必要的开销。给定数据模型，这些方法按需创建，配置和返回新的视图控制器。 * /

class ModelController：NSObject，UIPageViewControllerDataSource {

var pageData: [String] = []


override init() {
    super.init()
    // Create the data model.
    let dateFormatter = DateFormatter()
    pageData = dateFormatter.monthSymbols
}

func viewControllerAtIndex(_ index: Int, storyboard: UIStoryboard) -> DataViewController? {
    // Return the data view controller for the given index.
    if (self.pageData.count == 0) || (index >= self.pageData.count) {
        return nil
    }

    // Create a new view controller and pass suitable data.
    let dataViewController = storyboard.instantiateViewController(withIdentifier: "DataViewController") as! DataViewController
    dataViewController.dataObject = self.pageData[index]
    return dataViewController
}

func indexOfViewController(_ viewController: DataViewController) -> Int {
    // Return the index of the given data view controller.
    // For simplicity, this implementation uses a static array of model objects and the view controller stores the model object; you can therefore use the model object to identify the index.
    return pageData.index(of: viewController.dataObject) ?? NSNotFound
}

// MARK: - Page View Controller Data Source

func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
    var index = self.indexOfViewController(viewController as! DataViewController)
    if (index == 0) || (index == NSNotFound) {
        return nil
    }

    index -= 1
    return self.viewControllerAtIndex(index, storyboard: viewController.storyboard!)
}

func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
    var index = self.indexOfViewController(viewController as! DataViewController)
    if index == NSNotFound {
        return nil
    }

    index += 1
    if index == self.pageData.count {
        return nil
    }
    return self.viewControllerAtIndex(index, storyboard: viewController.storyboard!)
}

}

没有选中时，应用中的背景是什么？

0 个答案: