发现NSUserDefault值无效并杀死该应用程序

Question

I just trying to save the user Id and status as true value in UserDefaults when they login or Register with App.

UserDefaults.standard.set(user?.CustID, forKey: "CustID")
UserDefaults.standard.set(true, forKey: "status")

so when the user reopen the app in my Appdelegate I check the Status if it's true then user directly pass on HomeScreen and if the status False its pass on login screen.

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.

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

        if (status == true) && (custID != "") {
            let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
            let nextViewController = storyBoard.instantiateViewController(withIdentifier: "HomeTicketViewController") as! HomeTicketViewController
            let navigationController = UINavigationController(rootViewController: nextViewController)
            let appdelegate = UIApplication.shared.delegate as! AppDelegate
            appdelegate.window!.rootViewController = navigationController
        }else {
            let storyBoard : UIStoryboard = UIStoryboard(name: "Login", bundle:nil)
            let nextViewController = storyBoard.instantiateViewController(withIdentifier: "LoginViewController") as! LoginViewController
            let navigationController = UINavigationController(rootViewController: nextViewController)
            let appdelegate = UIApplication.shared.delegate as! AppDelegate
            appdelegate.window!.rootViewController = navigationController
        }
}

I get the status true but i found that The CustID found nil. Is there any solution for that?

Answer 1

In userdefault if value not found in userdefaults corresponding to key then userdefault return nil and in case of bool it returns false .

In your case, when you app launches, app does not have any value corresponding to custID so you getting nil .

You need to add check like this

if (status == true) && (custID != nil){
    :
    :
}

Answer 2

The default is false

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

so status will be false at first , also status being true doesn't mean CustID saved no nil

UserDefaults.standard.set(user!.CustID, forKey: "CustID")

as user may be nil so force-unwrap to verify that