iOS : getting crash while choosing that see pageviewcontroller for first time that apps loaded

Question

hi I followed some tutorial in stack for only seeing UIPageviewcontroller running at first time I find the best one and than implement it in app delegate .... first of all I have only one storyboard with two viewcontroller which first one is my PageViewController and second one is my Loginvc I implemented this code on appdelegate and I get crash everything looks good but I get crash this is the code that I have implement it

var window: UIWindow?
var story : UIStoryboard?


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

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

    let lunchedBefore = UserDefaults.standard.bool(forKey: "lunchedBefore")

    if lunchedBefore {
        story = UIStoryboard(name: "TShopUI", bundle: nil)
        let rootcontroller = story?.instantiateViewController(withIdentifier: "LoginVC")
        if let window = self.window {
            window.rootViewController = rootcontroller
        }
    } else {

        UserDefaults.standard.set(true, forKey: "lunchedBefore")
        story = UIStoryboard(name: "TShopUI", bundle: nil)
        let rootcontroller = story?.instantiateViewController(withIdentifier: "MainVC")

        if let window = self.window {
            window.rootViewController = rootcontroller
        }

    }
    return true
}

thanks for every help please answer as clear as you can I'm new to iOS development

yes the first time that I run app it crashes thanks for helping — Javad, Aug 23 '17 at 10:49
terminating with uncaught exception of type NSException. THIS MAIN ONE [UIStoryboard instantiateInitialViewController] and this one — Javad, Aug 23 '17 at 10:51
Look at this link https://stackoverflow.com/questions/13867565/what-is-a-storyboard-id-and-how-can-i-use-this Please note that identifier must be same in code as well as in Storyboard — Gagan_iOS, Aug 23 '17 at 10:56
the storyboard means that storyboardID in view controllers property — Javad, Aug 23 '17 at 11:07

Austin Michael · Accepted Answer · 2017-08-23T13:35:24.280

It's crashing because of UserDefaults, you have to handle UserDefaults like below,

Updated: instead of Bool we can use object. So Whether the if condition satisfies, it's not a first launch. else it's first launch.

var window: UIWindow?
var story : UIStoryboard?

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    UIApplication.shared.statusBarStyle = .lightContent
    window = UIWindow(frame: UIScreen.main.bounds)
    window?.makeKeyAndVisible()
    if let lunchedBefore = UserDefaults.standard.object(forKey: "lunchedBefore") {
        story = UIStoryboard(name: "TShopUI", bundle: nil)
        let rootcontroller = story?.instantiateViewController(withIdentifier: "LoginVC")
        if let window = self.window {
            window.rootViewController = rootcontroller
        }
    } else {
        UserDefaults.standard.set(true, forKey: "lunchedBefore")
        story = UIStoryboard(name: "TShopUI", bundle: nil)
        let rootcontroller = story?.instantiateViewController(withIdentifier: "MainVC")
        if let window = self.window {
            window.rootViewController = rootcontroller
        }
    }
    return true
}

thanks for help but it will give me this error Initializer for conditional binding must have Optional type, not 'Bool' — Javad, Aug 23 '17 at 10:54
add the answer that I added you answer is true but it should add storyboard id — Javad, Aug 23 '17 at 20:29

score 0 · Answer 2 · answered Aug 23 '17 at 20:27

0

the problem was that I should set a storyboard ID for each view controller and than in delegate set their identifier

answered Aug 23 '17 at 20:27

Javad

43
7

iOS : getting crash while choosing that see pageviewcontroller for first time that apps loaded

2 Answers2