iOS：在应用程序已被使用之前跳过ViewControllers

Question

我在XCode 8中工作。我的主要故事板中有三个ViewController。前两种是介绍屏幕，可以解释应用程序的功能等等。

是否有方法检查用户是否已经在某个时间范围内打开了应用程序（例如“今天”），如果是，跳过前两个屏幕？

（用户无需与帐户或东西登录。）

我的应用程序的方法是这样的：

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]? = nil) -> Bool { 

    //Requesting Authorization for User Interactions 
    let center = UNUserNotificationCenter.current() 
    center.requestAuthorization(options: [.alert, .sound]) { (granted, error) in 
     // Enable or disable features based on authorization. 
    } 

    // Override point for customization after application launch. 

    window = UIWindow(frame: UIScreen.main.bounds) 
    let userDefaults = UserDefaults.standard 
    let calendar = Calendar.current 
    if let lastOpened = userDefaults.object(forKey: "lastOpened") as? Date, calendar.isDateInToday(lastOpened) { 
     // app has been opened today 

     let myViewController = ViewController() 
     window?.rootViewController = myViewController 

    } else { 
     // app has not been opened today/not been opened at all 
     print("Alright, opening explanation screens") 
     let myViewController = StartViewController() 
     window?.rootViewController = myViewController 
    } 

    // save the current date for the next check 
    userDefaults.set(Date(), forKey: "lastOpened") 
    userDefaults.synchronize() 

    window?.makeKeyAndVisible() 

    return true 
} 

Answer 1

我在Android做同样的事情： 在启动应用程序我将检查SharedPreferences中是否有任何设置。在iOS上是相当于这个presented here如果不是一个“最后使用日期”比新安装，所以必须显示引言。别的，只需启动下一个屏幕即可。 够简单吗？ :)

Answer 2

是这样的：

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool { 
    // Override point for customization after application launch. 
    window = UIWindow(frame: UIScreen.main.bounds) 

    let userDefaults = UserDefaults.standard 

    let calendar = Calendar.current 
    if let lastOpened = userDefaults.object(forKey: "lastOpened") as? Date, calendar.isDateInToday(lastOpened) { 
     // app has been opened today 
     // set your rootViewController 
     // window.rootViewController = xyz 
    } else { 
     // app has not been opened today/not been opened at all 
     // set your rootViewController 
     // window.rootViewController = zyx 
    } 

    // save the current date for the next check 
    userDefaults.set(Date(), forKey: "lastOpened") 
    userDefaults.synchronize() 

    window?.makeKeyAndVisible() 

    return true 
}