iOS开发Swift-16-App的生命周期-AppDelegate和SceneDelegate
AppDelegate:
import UIKit import CoreData //包含App的部分生命周期函数(钩子函数),也有其余函数(如推送) @main class AppDelegate: UIResponder, UIApplicationDelegate { func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool { // Override point for customization after application launch. print("App启动") return true } // MARK: UISceneSession Lifecycle //iOS的App只有一个场景(只有一个窗口) 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. print("即将创建一个窗口时.在此可配置一个可视窗口") return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role) } 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. print("用户关闭了某个窗口") } // MARK: - Core Data stack lazy var persistentContainer: NSPersistentContainer = { /* The persistent container for the application. This implementation creates and returns a container, having loaded the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail. */ let container = NSPersistentContainer(name: "Todos") container.loadPersistentStores(completionHandler: { (storeDescription, error) in if let error = error as NSError? { // Replace this implementation with code to handle the error appropriately. // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. /* Typical reasons for an error here include: * The parent directory does not exist, cannot be created, or disallows writing. * The persistent store is not accessible, due to permissions or data protection when the device is locked. * The device is out of space. * The store could not be migrated to the current model version. Check the error message to determine what the actual problem was. */ fatalError("Unresolved error \(error), \(error.userInfo)") } }) return container }() // MARK: - Core Data Saving support func saveContext () { let context = persistentContainer.viewContext if context.hasChanges { do { try context.save() } catch { // Replace this implementation with code to handle the error appropriately. // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. let nserror = error as NSError fatalError("Unresolved error \(nserror), \(nserror.userInfo)") } } } }
SceneDelegate:
import UIKit //包含App的UI方面的生命周期函数,也有其余函数(如从别的App跳转回来时) 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). print("若使用IB,则自动创建可视窗口;若不使用IB,则可在此利用window属性(可视窗口),然后用代码设定App的首页vc") 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 necessarily discarded (see `application:didDiscardSceneSessions` instead). print("窗口/App已经断开连接(1.关闭App时调用,2.退到后台后不久调用)") } //App主要有三种状态:被关闭,在前台,在后台 //下面两个方法对应的范围更广,如App关闭时,用户点击推送横幅后打开App,也会调用sceneDidBecomeActive,此时可清楚右上角角标 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. print("窗口/App从非活跃-->活跃(已经被激活)") } 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). print("窗口/App从活跃-->非活跃(即将被挂起)") } 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. print("窗口/App从后台-->前台(即将回到前台)") } 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. print("窗口/App从前台-->后台(已经进入后台)") // Save changes in the application's managed object context when the application transitions to the background. (UIApplication.shared.delegate as? AppDelegate)?.saveContext() } }
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