set initial viewcontroller in appdelegate - swift

Question

I would like to set the initial viewcontroller from the appdelegate  I found a really good answer  however it s in Objective C and im having trouble achieving the same thing in swift   Programmatically set the initial view controller using Storyboards  -  BOOL application  UIApplication   application didFinishLaunchingWithOptions  NSDictionary  launchOptions       self window     UIWindow alloc  initWithFrame UIScreen mainScreen bounds        UIStoryboard  storyboard    UIStoryboard storyboardWithName   MainStoryboard  bundle nil        UIViewController  viewController      determine the initial view controller here and instantiate   it with  storyboard instantiateViewControllerWithIdentifier  lt storyboard id gt         self window rootViewController   viewController       self window makeKeyAndVisible        return YES      Anyone able to  help   I want the initial Viewcontroller to be dependent on certain conditions being met using a conditional statement

User · Answer

I had done in Xcode 8 and swift 3 0 hope it will be useful for u  and its working perfectly  Use following code     var window  UIWindow   func application   application  UIApplication  didFinishLaunchingWithOptions launchOptions   UIApplicationLaunchOptionsKey  Any    - gt  Bool              self window   UIWindow frame  UIScreen main bounds      let storyboard   UIStoryboard name   Main   bundle  nil      let initialViewController   storyboard instantiateViewController withIdentifier   ViewController       self window  rootViewController   initialViewController     self window  makeKeyAndVisible       return true     And If you are using the navigation controller  then use following code for that   var window  UIWindow   func application   application  UIApplication  didFinishLaunchingWithOptions launchOptions   UIApplicationLaunchOptionsKey  Any    - gt  Bool       self window   UIWindow frame  UIScreen main bounds      let storyboard   UIStoryboard name   Main   bundle  nil      let navigationController UINavigationController   storyboard instantiateInitialViewController   as  UINavigationController     let initialViewController   storyboard instantiateViewControllerWithIdentifier  ViewController       navigationController viewControllers    initialViewController      self window  rootViewController   navigationController     self window  makeKeyAndVisible             return true

User · Answer

For swift 4 0   In your AppDelegate swift file in didfinishedlaunchingWithOptions method  put the following code   var window  UIWindow    func application   application  UIApplication  didFinishLaunchingWithOptions launchOptions   UIApplicationLaunchOptionsKey  Any    - gt  Bool       window   UIWindow frame  UIScreen main bounds      window  makeKeyAndVisible        let rootVC   MainViewController      your custom viewController  You can instantiate using nib too  UIViewController nib name  bundle        let rootVC   UIViewController nibName   MainViewController   bundle  nil    or MainViewController       let navController   UINavigationController rootViewController  rootVC     Integrate navigation controller programmatically if you want      window  rootViewController   navController      return true     Hope it will work just fine

User · Answer

func application application  UIApplication  didFinishLaunchingWithOptions launchOptions   NSObject  AnyObject    - gt  Bool        self window   UIWindow frame  UIScreen mainScreen   bounds      let mainStoryboard  UIStoryboard   UIStoryboard name   Main   bundle  nil      var exampleViewController  ExampleViewController   mainStoryboard instantiateViewControllerWithIdentifier  ExampleController   as  ExampleViewController      self window  rootViewController   exampleViewController      self window  makeKeyAndVisible        return true

User · Answer

Swift 4      Add these lines inside AppDelegate swift  within the didFinishLaunchingWithOptions   function         func application   application  UIApplication  didFinishLaunchingWithOptions launchOptions   UIApplicationLaunchOptionsKey  Any    - gt  Bool           Setting the Appropriate initialViewController         Set the window to the dimensions of the device     self window   UIWindow frame  UIScreen main bounds          Grab a reference to whichever storyboard you have the ViewController within     let storyboard   UIStoryboard name   Name of Storyboard   bundle  nil          Grab a reference to the ViewController you want to show 1st      let initialViewController   storyboard instantiateViewController withIdentifier   Name of ViewController           Set that ViewController as the rootViewController     self window  rootViewController   initialViewController         Sets our window up in front     self window  makeKeyAndVisible        return true     Now  for example  many times we do something like this when we want to either drive the user to a login screen or to a initial setup screenl or back to the mainScreen of the app  etc  If you want to do something like that too  you can use this point as a fork-in-the-road for that   Think about it  You could have a value stored in NSUserDefaults for instance that held a userLoggedIn Boolean and if userLoggedIn    false   use this storyboard  amp  initialViewController      else   use this storyboard  amp  initialViewController

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Just in case you want to do it in the view controller and not in the app delegate  Just fetch the reference to the AppDelegate in your view controller and reset it s window object with the right view controller as it s rootviewController   let appDelegate   UIApplication sharedApplication   delegate as  AppDelegate appDelegate window   UIWindow frame  UIScreen mainScreen   bounds  let mainStoryboard  UIStoryboard   UIStoryboard name   Main   bundle  nil  let yourVC   mainStoryboard instantiateViewControllerWithIdentifier  YOUR VC IDENTIFIER   as  YourViewController appDelegate window  rootViewController   yourVC appDelegate window  makeKeyAndVisible

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Code for Swift 4 2 and 5 code    var window  UIWindow    func application   application  UIApplication  didFinishLaunchingWithOptions launchOptions   UIApplicationLaunchOptionsKey  Any    - gt  Bool         self window   UIWindow frame  UIScreen main bounds        let storyboard   UIStoryboard name   Main   bundle  nil        let initialViewController   storyboard instantiateViewController withIdentifier   dashboardVC         self window  rootViewController   initialViewController      self window  makeKeyAndVisible       And for Xcode 11  and for Swift 5     class SceneDelegate  UIResponder  UIWindowSceneDelegate         var window  UIWindow        func scene   scene  UIScene  willConnectTo session  UISceneSession  options connectionOptions  UIScene ConnectionOptions             if let windowScene   scene as  UIWindowScene                let window   UIWindow windowScene  windowScene                 window rootViewController      Your RootViewController in here                self window   window               window makeKeyAndVisible

User · Answer

Disable Main storyboard  General - gt  Deployment Info - gt  Main Interface - gt  remove  Main   Info plist - gt  remove Key Value for  UISceneStoryboardFile  and   UIMainStoryboardFile    Add Storyboard ID  Main storyboard - gt  Select View Controller - gt  Inspectors - gt  Identity inspector - gt  Storyboard ID - gt  e g  customVCStoryboardId   Swift 5 and Xcode 11  Extend UIWindow  class CustomWindow   UIWindow                 Edit generated by Xcode SceneDelegate swift  class SceneDelegate  UIResponder  UIWindowSceneDelegate        var window  CustomWindow       func scene   scene  UIScene  willConnectTo session  UISceneSession  options connectionOptions  UIScene ConnectionOptions             guard let windowScene    scene as  UIWindowScene  else   return            let storyboard   UIStoryboard name   Main   bundle  nil          let initialViewController   storyboard instantiateViewController withIdentifier   customVCStoryboardId            window   CustomWindow windowScene  windowScene          window rootViewController   initialViewController         window makeKeyAndVisible

User · Answer

For Swift 5   var window  UIWindow       func scene   scene  UIScene  willConnectTo session  UISceneSession  options connectionOptions  UIScene ConnectionOptions            if let windowScene   scene as  UIWindowScene               let window   UIWindow windowScene  windowScene              let submodules                     home  HomeRouter createModule                    search  SearchRouter createModule                    exoplanets  ExoplanetsRouter createModule                                          let tabBarController   TabBarModuleBuilder build usingSubmodules  submodules                           window rootViewController   tabBarController             self window   window             window makeKeyAndVisible

User · Answer

Try this  For example  You should use UINavigationController as the initial view controller  Then   you can set any view controller as root from the storyboard  func application application  UIApplication  didFinishLaunchingWithOptions launchOptions   NSObject  AnyObject    - gt  Bool          Override point for customization after application launch      let storyboard   UIStoryboard name   quot Main quot   bundle  nil      let navigationController   storyboard instantiateInitialViewController   as UINavigationController     let rootViewController   storyboard instantiateViewControllerWithIdentifier  quot VC quot   as UIViewController     navigationController viewControllers    rootViewController      self window  rootViewController   navigationController     return true    See my storyboard screen

User · Answer

Here is complete Solution in Swift 4 implement this in didFinishLaunchingWithOptions   func application   application  UIApplication  didFinishLaunchingWithOptions launchOptions   UIApplicationLaunchOptionsKey  Any    - gt  Bool     let isLogin   UserDefaults standard bool forKey   Islogin       if isLogin          self NextViewController storybordid   OtherViewController          else          self NextViewController storybordid   LoginViewController              write this Function any where inside Appdelegate swift    func NextViewController storybordid String         let storyBoard UIStoryboard   UIStoryboard name   Main   bundle  nil      let exampleVC   storyBoard instantiateViewController withIdentifier storybordid         self present exampleVC  animated  true      self window   UIWindow frame  UIScreen main bounds      self window  rootViewController   exampleVC     self window  makeKeyAndVisible

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I worked out a solution on Xcode 6 4 in swift       I saved the credentials on a click event to phone memory       IBAction func gotobidderpage sender  AnyObject     if  usernamestring     bidder   amp  amp  passwordstring     day303                         rolltype    1   NSUserDefaults standardUserDefaults   setObject usernamestring  forKey   username   NSUserDefaults standardUserDefaults   setObject passwordstring  forKey   password   NSUserDefaults standardUserDefaults   setObject rolltype  forKey   roll                 self performSegueWithIdentifier  seguetobidderpage   sender  self         Retained saved credentials in app delegate swift and performed navigation after condition check       func application application  UIApplication  didFinishLaunchingWithOptions launchOptions   NSObject  AnyObject    - gt  Bool    let usernamestring   NSUserDefaults standardUserDefaults   stringForKey  username   let passwordstring   NSUserDefaults standardUserDefaults   stringForKey  password   let rolltypestring   NSUserDefaults standardUserDefaults   stringForKey  roll            if  usernamestring     bidder   amp  amp  passwordstring     day303   amp  amp  rolltypestring     1                             Access the storyboard and fetch an instance of the view controller             var storyboard   UIStoryboard name   Main   bundle  nil              var viewController  BidderPage   storyboard instantiateViewControllerWithIdentifier  bidderpageID   as  BidderPage                 Then push that view controller onto the navigation stack             var rootViewController   self window  rootViewController as  UINavigationController             rootViewController pushViewController viewController  animated  true                        Override point for customization after application launch          return true          Hope it helps

User · Answer

I used this thread to help me convert the objective C to swift  and its working perfectly   Instantiate and Present a viewController in Swift  Swift 2 code    func application application  UIApplication  didFinishLaunchingWithOptions launchOptions   NSObject  AnyObject    - gt  Bool       self window   UIWindow frame  UIScreen mainScreen   bounds       let storyboard   UIStoryboard name   Main   bundle  nil       let initialViewController   storyboard instantiateViewControllerWithIdentifier  LoginSignupVC        self window  rootViewController   initialViewController     self window  makeKeyAndVisible        return true     Swift 3 code   func application   application  UIApplication  didFinishLaunchingWithOptions launchOptions   UIApplicationLaunchOptionsKey  Any    - gt  Bool       self window   UIWindow frame  UIScreen main bounds       let storyboard   UIStoryboard name   Main   bundle  nil       let initialViewController   storyboard instantiateViewController withIdentifier   LoginSignupVC        self window  rootViewController   initialViewController     self window  makeKeyAndVisible        return true

User · Answer

Here is a good way to approach it   This example places a navigation controller as the root view controller  and puts the view controller of your choice within it at the bottom of the navigation stack  ready for you to push whatever you need to from it   func application application  UIApplication  didFinishLaunchingWithOptions launchOptions   NSObject  AnyObject    - gt  Bool          mainStoryboard     let mainStoryboard   UIStoryboard name   MainStoryboard   bundle  nil          rootViewController     let rootViewController   mainStoryboard instantiateViewControllerWithIdentifier  MainViewController   as  UIViewController         navigationController     let navigationController   UINavigationController rootViewController  rootViewController        navigationController navigationBarHidden   true    or not  your choice          self window     self window   UIWindow frame  UIScreen mainScreen   bounds       self window  rootViewController   navigationController      self window  makeKeyAndVisible       To make this example work you would set  MainViewController  as the Storyboard ID on your main view controller  and the storyboard s file name in this case would be  MainStoryboard storyboard    I rename my storyboards this way because Main storyboard to me is not a proper name  particularly if you ever go to subclass it

User · Answer

If you re not using the storyboard  You can initialize your main view controller programmatically   Swift 4  func application   application  UIApplication  didFinishLaunchingWithOptions launchOptions   UIApplication LaunchOptionsKey  Any    - gt  Bool        let rootViewController   MainViewController       let navigationController   UINavigationController rootViewController  rootViewController      self window   UIWindow frame  UIScreen main bounds      self window  rootViewController   navigationController     self window  makeKeyAndVisible        return true     class MainViewController  UIViewController        override func viewDidLoad             super viewDidLoad            view backgroundColor    green           And also remove Main from Deployment Info

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iOS 13  In the SceneDelegate  var window  UIWindow   func scene   scene  UIScene  willConnectTo session  UISceneSession  options  connectionOptions  UIScene ConnectionOptions        guard let windowScene    scene as  UIWindowScene  else   return       window   UIWindow windowScene  windowScene      let vc   UIViewController     Instead of UIViewController   we initilise our initial viewController     window  rootViewController   vc     window  makeKeyAndVisible

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Open a viewcontroller with SWRevealViewController From App delegate    self window   UIWindow frame  UIScreen main bounds   let storyboard   UIStoryboard name   StoryboardName   bundle  nil   let swrevealviewcontroller SWRevealViewController   storyboard instantiateInitialViewController   as  SWRevealViewController   self window  rootViewController   swrevealviewcontroller  self window  makeKeyAndVisible

User · Answer

For new Xcode 11 xxx and Swift 5 xx  where the target it set to iOS 13    For the new project structure  AppDelegate does not have to do anything regarding rootViewController   A new class is there to handle window UIWindowScene  class -   SceneDelegate  file   class SceneDelegate  UIResponder  UIWindowSceneDelegate   var window  UIWindow   func scene   scene  UIScene  willConnectTo session  UISceneSession  options connectionOptions  UIScene ConnectionOptions         if let windowScene   scene as  UIWindowScene           let window   UIWindow windowScene  windowScene          window rootViewController      Your RootViewController in here         self window   window         window makeKeyAndVisible

User · Answer

Well all the answers above below are producing a warning about no entry point in storyboard   If you want to have 2  or more  entry view controllers that depend on some condition  say conditionVariable  then what you should do is    In your Main storyboard create UINavigationController without rootViewController  set it as entry point Create 2  or more   Show  segues into view controllers  assign them some id  say id1 and id2 Use next code   class AppDelegate  UIResponder  UIApplicationDelegate       var window  UIWindow      func application application  UIApplication  didFinishLaunchingWithOptions launchOptions   NSObject  AnyObject    - gt  Bool          let navigationController   window  rootViewController  as  UINavigationController        navigationController performSegueWithIdentifier conditionVariable    id1     id2           return true         Hope this helps

User · Answer

if you are not using storyboard  you can try this  var window  UIWindow  var initialViewController  UIViewController   func application application  UIApplication  didFinishLaunchingWithOptions launchOptions   NSObject  AnyObject    - gt  Bool        initialViewController    MainViewController nibName  MainViewController  bundle nil       let frame   UIScreen mainScreen   bounds     window   UIWindow frame  frame       window  rootViewController   initialViewController     window  makeKeyAndVisible        return true

User · Answer

Swift 5  amp  Xcode 11  So in xCode 11 the window solution is no longer valid inside of appDelegate   They moved this to the SceneDelgate   You can find this in the SceneDelgate swift file   You will notice it now has a var window  UIWindow  present   In my situation I was using a TabBarController from a storyboard and wanted to set it as the rootViewController   This is my code   sceneDelegate swift  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            self window   self window    UIWindow     JA- If this scene s self window is nil then set a new UIWindow object to it              Grab the storyboard and ensure that the tab bar controller is reinstantiated with the details below          let storyboard   UIStoryboard name   Main   bundle  nil          let tabBarController   storyboard instantiateViewController withIdentifier   tabBarController   as  UITabBarController          for child in tabBarController viewControllers                     if let top   child as  StateControllerProtocol                   print  State Controller Passed To                    print child title                   top setState state  stateController                                   self window  rootViewController   tabBarController   Set the rootViewController to our modified version with the StateController instances         self window  makeKeyAndVisible            print  Finished scene setting code           guard let      scene as  UIWindowScene  else   return           Make sure to add this to the correct scene method as I did here   Note that you will need to set the identifier name for the tabBarController or viewController you are using in the storyboard     In my case I was doing this to set a stateController to keep track of shared variables amongst the tab views   If you wish to do this same thing add the following code     StateController swift  import Foundation  struct tdfvars      var rbe Double   1 4     var t1half Double   1 5     var alphaBetaLate Double   3 0     var alphaBetaAcute Double   10 0     var totalDose Double   6000 00     var dosePerFraction Double   200 0     var numOfFractions Double   30     var totalTime Double   168     var ldrDose Double   8500 0       JA - Protocol that view controllers should have that defines that it should have a function to setState protocol StateControllerProtocol     func setState state  StateController     class StateController       var tdfvariables tdfvars   tdfvars       Note  Just use your own variables or whatever you are trying to keep track of instead  I just listed mine as an example in tdfvariables struct   In each view of the TabController add the following member variable       class SettingsViewController  UIViewController       var stateController  StateController           Then in those same files add the following   extension SettingsViewController  StateControllerProtocol     func setState state  StateController        self stateController   state         What this does is allows you to avoid the singleton approach to passing variables between the views   This allows easily for the dependency injection model which is much better long run then the singleton approach

User · Answer

I find this answer helpful and works perfectly for my case when i needed to change the rootviewcontroller if my app user already exist in the keychain or userdefault  https   stackoverflow com a 58413582 6596443

User · Answer

I had done it in Objective-C  I hope it will be useful for you  UIStoryboard  storyboard    UIStoryboard storyboardWithName   quot Main quot  bundle nil    UIViewController  viewController   NSUserDefaults  loginUserDefaults    NSUserDefaults standardUserDefaults   NSString  check  loginUserDefaults objectForKey   quot Checklog quot     if   check isEqualToString   quot login quot               viewController    storyboard instantiateViewControllerWithIdentifier   quot SWRevealViewController quot      else            viewController    storyboard instantiateViewControllerWithIdentifier   quot LoginViewController quot        self window rootViewController   viewController   self window makeKeyAndVisible

User · Answer

Swift 3  Swift 4  Change first line to func application   application  UIApplication  didFinishLaunchingWithOptions launchOptions   UIApplicationLaunchOptionsKey  Any    - gt  Bool  the rest is same  Swift 5   Instantiate root view controller from storyboard  func application   application  UIApplication  didFinishLaunchingWithOptions launchOptions   UIApplication LaunchOptionsKey  Any    - gt  Bool              this line is important         self window   UIWindow frame  UIScreen main bounds              In project directory storyboard looks like Main storyboard             you should use only part before  quot  storyboard quot  as its name             so in this example name is  quot Main quot           let storyboard   UIStoryboard init name   quot Main quot   bundle  nil                      controller identifier sets up in storyboard utilities            panel  on the right   it is called  Storyboard ID          let viewController   storyboard instantiateViewController withIdentifier   quot YourViewControllerIdentifier quot   as  YourViewController          self window  rootViewController   viewController         self window  makeKeyAndVisible                   return true        If you want to use UINavigationController as root  func application   application  UIApplication  didFinishLaunchingWithOptions launchOptions   UIApplication LaunchOptionsKey  Any    - gt  Bool              this line is important         self window   UIWindow frame  UIScreen main bounds           let storyboard   UIStoryboard init name   quot Main quot   bundle  nil          let viewController   storyboard instantiateViewController withIdentifier   quot YourViewControllerIdentifier quot   as  YourViewController         let navigationController   UINavigationController init rootViewController  viewController          self window  rootViewController   navigationController          self window  makeKeyAndVisible                   return true        Instantiate root view controller from xib  It is almost the same  but instead of lines let storyboard   UIStoryboard init name   quot Main quot   bundle  nil  let viewController   storyboard instantiateViewController withIdentifier   quot YourViewControllerIdentifier quot   as  YourViewController  you ll have to write let viewController   YourViewController nibName   quot YourViewController quot   bundle  nil

[ios] set initial viewcontroller in appdelegate - swift

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