Migración del antiguo proyecto Xcode a uno nuevo con UISceneDelegate

Question

Tengo un antiguo proyecto de Xcode sin UISceneDelegatemétodos. ¿Es posible migrar un proyecto antiguo de Xcode a uno nuevo con UISceneDelegatemétodos PERO manteniendo la compatibilidad con iOS 12?

¿Si es así, cómo? Porque veo muchos errores en iOS 14 para los cuales la única solución es usar métodos UISceneDelegate.

Answer 1

EDITAR 1:

Asegúrese de consultar windowOrientation, después de que se renderice la vista del controlador de vista. Normalmente en viewDidLoad()y viewWillAppear(_:), view.windowes nil, verifique esta respuesta . Solo verifique el valor windowOrientationen viewDidAppear(_:).

Si tiene algunos problemas para acceder a este valor incluso antes, pruebe la siguiente definición

private var windowOrientation: UIInterfaceOrientation {
    if #available(iOS 13.0, *) {
        return UIApplication.shared.windows.first?.windowScene?.interfaceOrientation ?? .unknown
    } else {
        // Fallback on earlier versions
        return UIApplication.shared.statusBarOrientation
    }
}

No estoy seguro de si su aplicación usa múltiples ventanas o no, pero si solo hay una (ya que no está creando ninguna ventana mediante programación), la siguiente definición debería funcionar bien.

var hasTopNotch: Bool {
    return UIApplication.shared.windows.first?.safeAreaInsets.top ?? 0 > 20
}

Respuesta original:

UISceneDelegatese ha introducido de iOS 13.0manera que no es compatible con él iOS 12, debe depender UIApplicationDelegatetotalmente de él. Para admitir UISceneDelegateen iOS 13.x, debe agregar una verificación de disponibilidad explícita para evitar errores de compilación.

Pasos 1: Agregue el manifiesto de escena en Info.plist

Abrir Info.plistcomo Source Codey agregar lo siguiente

<key>UIApplicationSceneManifest</key>
<dict>
    <key>UIApplicationSupportsMultipleScenes</key>
    <false/>
    <key>UISceneConfigurations</key>
    <dict>
        <key>UIWindowSceneSessionRoleApplication</key>
        <array>
            <dict>
                <key>UISceneConfigurationName</key>
                <string>Default Configuration</string>
                <key>UISceneDelegateClassName</key>
                <string>$(PRODUCT_MODULE_NAME).SceneDelegate</string>
                <key>UISceneStoryboardFile</key>
                <string>Main</string>
            </dict>
        </array>
    </dict>
</dict>

Paso 2: crea un SceneDelegate.swiftarchivo con el siguiente contenido

import UIKit
@available(iOS 13.0, *)
class SceneDelegate: UIResponder, UIWindowSceneDelegate {

    var window: UIWindow?


    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 _ = (scene as? UIWindowScene) else { return }
    }

    func sceneDidDisconnect(_ scene: UIScene) {
        // Called as the scene is being released by the system.
        // This occurs shortly after the scene enters the background, or when its session is discarded.
        // Release any resources associated with this scene that can be re-created the next time the scene connects.
        // The scene may re-connect later, as its session was not neccessarily discarded (see `application:didDiscardSceneSessions` instead).
    }

    func sceneDidBecomeActive(_ scene: UIScene) {
        // Called when the scene has moved from an inactive state to an active state.
        // Use this method to restart any tasks that were paused (or not yet started) when the scene was inactive.
    }

    func sceneWillResignActive(_ scene: UIScene) {
        // Called when the scene will move from an active state to an inactive state.
        // This may occur due to temporary interruptions (ex. an incoming phone call).
    }

    func sceneWillEnterForeground(_ scene: UIScene) {
        // Called as the scene transitions from the background to the foreground.
        // Use this method to undo the changes made on entering the background.
    }

    func sceneDidEnterBackground(_ scene: UIScene) {
        // Called as the scene transitions from the foreground to the background.
        // Use this method to save data, release shared resources, and store enough scene-specific state information
        // to restore the scene back to its current state.
    }


}

Paso 3: actualización AppDelegate

1. Agregue UISceneSession Lifecyclemétodos.

// MARK: UISceneSession Lifecycle
@available(iOS 13.0, *)
func application(_ application: UIApplication, configurationForConnecting connectingSceneSession: UISceneSession, options: UIScene.ConnectionOptions) -> UISceneConfiguration {
    // Called when a new scene session is being created.
    // Use this method to select a configuration to create the new scene with.
    return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role)
}
@available(iOS 13.0, *)
func application(_ application: UIApplication, didDiscardSceneSessions sceneSessions: Set<UISceneSession>) {
    // Called when the user discards a scene session.
    // If any sessions were discarded while the application was not running, this will be called shortly after application:didFinishLaunchingWithOptions.
    // Use this method to release any resources that were specific to the discarded scenes, as they will not return.
}

ii) Por último, consulte la documentación de Apple . Puede referirse ahttps://dev.to/kevinmaarek/add-a-scene-delegate-to-your-current-project-5on para tareas adicionales de limpieza y configuración.