Swift: 使Navigation Controller中嵌入的UITableViewController的背景图充满整个屏幕

Swift: Make the background image of UITableViewController embedded in Navigation Controller fill the entire screen

我设法在嵌入导航控制器的 UITableViewController 中创建半透明和圆形的 UITableViewCells,并在 viewDidLoad():

中使用这行代码
    tableView.backgroundView = UIImageView(image: UIImage(named: "nightTokyo"))

但我希望背景图片填满整个 phone 屏幕。我将代码(和这行代码)更改为:

    navigationController?.view = UIImageView(image: UIImage(named: "nightTokyo"))

现在背景图像填满了整个 phone 屏幕,但是我的 table 甚至 iPhone 的时间和电池指示器图标都不见了。

我想要的是背景图片填满整个屏幕,但 tableView、它的单元格、iPhone 时间、电池电量图标等保持显示。

navigationController?.setNavigationBarHidden(true, animated: true)

这是我使用 Swift 5, XCode 12.

对我有用的方法

第 1 步(可选)- 创建自定义 UINavigationController class

class CustomNavigationController: UINavigationController {
  override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    navigationBar.isTranslucent = true
}

用这个 UINavigationController subclass 替换你的 UINavigationController。我将其标记为可选,因为这是基于偏好的,如果你不设置它,你的导航栏将是不透明的,你看不到它下面的内容。

设置navigationBar.isTranslucent = true可以让你看到它下面的背景,这是我喜欢的。 subclass 也是可选的,但您可能需要对导航栏进行其他更新,所以我总是喜欢将其设为 subclass.

第 2 步 - 设置背景视图约束

class CustomViewController: UIViewController {
  // your background view
  let bgImageView: UIImageView = {
    let bgImageView = UIImageView()
    bgImageView.image = UIImage(named: "gradient_background")
    bgImageView.contentMode = .scaleAspectFill
    return bgImageView
}()

  // Get the height of the nav bar and the status bar so you
  // know how far up your background needs to go
  var topBarHeight: CGFloat {
    var top = self.navigationController?.navigationBar.frame.height ?? 0.0
    if #available(iOS 13.0, *) {
      top += UIApplication.shared.windows.first?.windowScene?.statusBarManager?.statusBarFrame.height ?? 0
    } else {
      top += UIApplication.shared.statusBarFrame.height
    }
    return top
  }

  var isLayoutConfigured = false

  override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    title = "Site Visit"

    // you only want to do this once
    if !isLayoutConfigured() {
      isLayoutConfigured = true
      configBackground()
    }
  }

  private func configBackground() {
    view.addSubview(bgImageView)
    configureBackgroundConstraints()
  }
  
  // Set up your constraints, main one here is the top constraint
  private func configureBackgroundConstraints() {
    bgImageView.translatesAutoresizingMaskIntoConstraints = false
    bgImageView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor,
                                     constant: -topBarHeight).isActive = true
    bgImageView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor,
                                         constant: 0).isActive = true
    bgImageView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor,
                                        constant: 0).isActive = true
    bgImageView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor,
                                          constant: 0).isActive = true
    
    view.layoutIfNeeded()
}

设置约束前:

设置以上约束后: