iOS应用如何只镜像到苹果电视而不占据整个屏幕？

Question

我有一个 iOS 应用程序，当它通过 Airplay 镜像到 Apple TV 时，它实际上占据了整个电视屏幕，就好像 UIKit 正在读取电视的实际尺寸一样。然而，这不是我想要的 - 我只想镜像应用程序以适应电视屏幕（像大多数其他应用程序一样）并显示黑色区域。我该怎么做？

编辑：澄清一下，我只想按原样镜像屏幕，而不是尝试显示任何其他内容。

编辑2：

我在 App/SceneDelegate 中做的唯一一件事是以编程方式设置委托类（因为我不想在 plist 中设置它）：

在我的应用程序委托中：

  public func application(_ application: UIApplication, configurationForConnecting connectingSceneSession: UISceneSession, options: UIScene.ConnectionOptions) -> UISceneConfiguration {
    // Since we manually create the config instead of reading "DefaultConfiguration" from Info.Plist, we should delete the entry in info.plist.
    let config = UISceneConfiguration(name: nil, sessionRole: connectingSceneSession.role)
    config.delegateClass = Self.self
    config.sceneClass = UIWindowScene.self
    return config
  }

在我的场景中代表：

  public func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
    // Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
    // If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
    // This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
    guard let windowScene = (scene as? UIWindowScene) else { return }
    let window = UIWindow(windowScene: windowScene)
    
    window.rootViewController = rootVC()
    window.makeKeyAndVisible()
    window.overrideUserInterfaceStyle = .light
  }

然后我的 plist 的“应用程序场景清单”删除了类设置：

Answer 1

在代码中的某个时刻，您正在设置用于外部显示器的窗口。这里您需要使用设备的大小创建一个窗口。

您可以使用主屏幕的框架实例化窗口，如下所示：

window = UIWindow(frame: UIScreen.main.bounds)

Answer 2

终于找到问题了。这是因为当使用airplay时，

willConnectTo

会再次被

session.role == .windowExternalDisplayNonInteractive

调用。我们需要检查

session.role

，并在这种情况下提前返回：

  public func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
    
    // willConnectTo is called again when connect to an external display (airplay), with a different role type.
    // If we don't do anything, iOS will simply mirror the screen.
    guard session.role == .windowApplication else {
      return
    }
    // Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
    // If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
    // This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
    guard let windowScene = (scene as? UIWindowScene) else { return }
    let window = UIWindow(windowScene: windowScene)
    
    window.rootViewController = rootVC()
    window.makeKeyAndVisible()
    window.overrideUserInterfaceStyle = .light  
  }

Answer 3

要实现将 iOS 应用程序镜像到具有黑色区域的 Apple TV 屏幕而不是占据整个屏幕的所需行为，您可以按照以下步骤操作：

1. 确定 Apple TV 的屏幕分辨率。大多数 Apple TV 的默认分辨率为 1920x1080 像素，即长宽比为 16:9。不过，以编程方式获取实际屏幕尺寸以考虑不同 Apple TV 型号或未来潜在更新的差异始终是一个好习惯。

2. 修改 iOS 应用程序的视图层次结构以匹配 Apple TV 屏幕的宽高比。一种方法是将应用程序的内容嵌入到保持所需宽高比（在本例中为 16:9）的容器视图中。您可以在内容视图周围添加黑色区域（具有黑色背景颜色的 UIView）以填充剩余空间。

以下是如何以编程方式执行此操作的示例：

class ViewController: UIViewController {
    // Container view to maintain the aspect ratio of the Apple TV screen
    let containerView = UIView()

    override func viewDidLoad() {
        super.viewDidLoad()

        // Set up the container view
        containerView.translatesAutoresizingMaskIntoConstraints = false
        containerView.backgroundColor = .black

        // Add the container view to the main view
        view.addSubview(containerView)

        // Configure constraints to maintain aspect ratio and fill the screen
        NSLayoutConstraint.activate([
            containerView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            containerView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            containerView.topAnchor.constraint(equalTo: view.topAnchor),
            containerView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
        ])

        // Add your app's content view to the container view
        let contentView = UIView()
        contentView.translatesAutoresizingMaskIntoConstraints = false
        contentView.backgroundColor = .red // Replace with your actual content view
        containerView.addSubview(contentView)

        // Configure constraints for the content view
        NSLayoutConstraint.activate([
            contentView.centerXAnchor.constraint(equalTo: containerView.centerXAnchor),
            contentView.centerYAnchor.constraint(equalTo: containerView.centerYAnchor),
            contentView.widthAnchor.constraint(equalTo: contentView.heightAnchor, multiplier: 16.0 / 9.0) // Aspect ratio of 16:9
        ])
    }
}

通过将应用程序的内容嵌入到容器视图中，您可以确保它在 Apple TV 屏幕上保持所需的宽高比。黑色区域填充剩余空间，为您的应用程序的内容提供宽高比匹配的效果。