UIPageViewController显示黑屏

Question

运行时，我的UIPageViewController显示为黑色屏幕。

它是应用程序委托中设置的根视图控制器：

    window = UIWindow()
    let mainPageViewController = MainPageViewController(transitionStyle: .scroll, navigationOrientation: .horizontal, options: nil)
    window?.rootViewController = mainPageViewController

这是我的MainPageViewController代码：

class MainPageViewController: UIPageViewController, UIPageViewControllerDataSource 
{
    override func viewDidLoad()
    {
        super.viewDidLoad()

        dataSource = self

        let profileController = ProfileController()
        let viewControllers = [profileController]
        self.setViewControllers(viewControllers, direction: .forward, animated: true, completion: nil)
    }

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

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

我试图将profilecontroller设置为初始页面，它是一个普通的UIViewController。

我试过很多东西，但它总是显示一个黑色的屏幕。知道我做错了什么吗？

Answer 1

你的PageViewController很好。但是，设置rootViewController的过程遗漏了以下内容：

window = UIWindow()
let mainPageViewController = MainPageViewController(transitionStyle: .scroll, navigationOrientation: .horizontal, options: nil)
window?.rootViewController = mainPageViewController
// This line will make it visible
window?.makeKeyAndVisible()

Answer 2

试试这个：-

self.window = UIWindow(frame:  UIScreen.main.bounds)
    let mainPageViewController = MainPageViewController(transitionStyle: .scroll, navigationOrientation: .horizontal, options: nil)
    window?.rootViewController = mainPageViewController
    self.window?.makeKeyAndVisible()

Answer 3

我不知道您的问题是什么，如果您的问题是you don't know why your screen is black?，我认为您应该在appDelegate中设置它：

window.backgroundColor = .white

这个给你的控制器：

self.view.backgroundColor = .white