PageViewController 显示部分其他 viewcontroller

Question

我有一个 UIPageViewController 和 2 个 UIViewControllers，它们都有一个 UIImageView 作为背景，内容模式设置为 scaleAspectFill。由于某些原因，当首先滚动到第二个 UIViewController 而不是滚动回第一个 UIViewController.

时，第二个 UIViewController 部分可见

复制项目可以在这里找到：https://github.com/Jasperav/PageViewControllerGlitch。密码也在照片下方。

照片（space第一张UIViewController，绿色部分是第二张UIViewController）：

代码（我不使用故事板，对于具有正确window的再现路径，使用github link）：

import UIKit

class PageViewController: UIPageViewController, UIPageViewControllerDataSource, UIPageViewControllerDelegate {

    private let pageViewControllers: [UIViewController] = [VC1(), VC2()]

    init() {
        super.init(transitionStyle: .scroll, navigationOrientation: .horizontal, options: nil)

        dataSource = self
        delegate = self

        setViewControllers([pageViewControllers.first!], direction: .forward, animated: false, completion: nil)
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

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

    func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
        guard let index = pageViewControllers.index(of: viewController), index > 0 else { return nil }

        let previousIndex = index - 1

        return pageViewControllers[previousIndex]
    }

    func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
        guard let index = pageViewControllers.index(of: viewController), (index + 1) != pageViewControllers.count else { return nil }

        return pageViewControllers[index + 1]
    }
}

class VC: UIViewController {
    init(background: UIImage) {
        super.init(nibName: nil, bundle: nil)

        let backgroundImageView = UIImageView(image: background)

        backgroundImageView.contentMode = .scaleAspectFill

        view.addSubview(backgroundImageView)

        backgroundImageView.translatesAutoresizingMaskIntoConstraints = false

        backgroundImageView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
        backgroundImageView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
        backgroundImageView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
        backgroundImageView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

class VC1: VC {
    init() {
        super.init(background: #imageLiteral(resourceName: "bg1"))
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

class VC2: VC {
    init() {
        super.init(background: #imageLiteral(resourceName: "bg2"))
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

Answer 1

当您使用AspectFill 作为内容模式时，如果图像大于UImageView 的尺寸，图像会溢出。要解决此问题，您可以剪辑其子视图：

backgroundImageView.contentMode = .scaleAspectFill
backgroundImageView.clipsToBounds = true

另一种解决方案是尝试另一种内容模式，如 .scaleToFill。希望这有帮助，我刚刚在您的演示项目中尝试了这个解决方案并且都有效。

PageViewController 显示部分其他 viewcontroller

PageViewController shows part of other viewcontroller

swift

uipageviewcontroller