So, I'm trying to instantiate my view controller programmatically using storyboard references.
I've put this code in the AppDelegate:
var window: UIWindow?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
window = UIWindow(frame: UIScreen.main.bounds)
let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let initialController: WelcomePageViewController = mainStoryboard.instantiateViewController(withIdentifier: "WelcomePageViewController") as! UITabBarController
window?.rootViewController = initialController
window?.makeKeyAndVisible()
return true
}
And set this inside my view controller's storyboard:
However when I run the application, only a black screen is shown and this message:
"Failed to instantiate the default view controller for UIMainStoryboardFile 'Main' - perhaps the designated entry point is not set?"
I've used this exact code in other apps and it works just fine.
I've tried to clean build folder, to run it on an actual device and to create and instantiate a different storyboard file but nothing worked.
Open your Main.storyboard file and find WelcomePageViewController. When it’s selected, go to the attributes inspector and check the box marked Is Initial View Controller.
You should see a right-facing arrow appear to the left of WelcomePageViewController, showing that it’s your storyboard’s entry point.
Now you're all set to go!!!
Ok So i think here is something you can do if it suits:
set entry point to the navigation controller
class that navigation controller with a file like rootNavigationVC.swift which is subclass of UINavigationController
now in didLoad() you can set it's viewController or push one based on your condition
trust me its better than coding in AppDelegate.swift which never worked for me.
Related
Short question:
How can I launch and make a UITabBarController be the rootViewController of my app after starting with a Storyboard?
Long question:
I'm not a swift expert, but I managed to create a complete app using XIBs from the beginning. Now I need my app to start with a Storyboard as a new requirement to post updates to the appstore from 01/07/2020, but I never used it to build my views. It was easy to modify my app to have my Storyboard as an entry point, but the problem is that my initial view today is a TabController, and I don't know how to navigate from my initial Storyboard to my TabController.
My AppDelegate today works something like this:
var window: UIWindow?
func application(_application: UIApplication, didFinishLauchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
self.window = UIWindow(frame: UIScreen.main.bounds)
// initiate UINavigationControllers and UITabBarController here...
tabController.viewController = [nav1, nav2, nav3, nav4]
tabController.modalPresentationStyle = .fullScreen
self.window!.rootViewController = tabController
self.window!.makeKeyAndVisible()
}
All my attempts ended with a white screen after showing my Storyboard without showing my TabBar.
One of these attempts was this:
override func loadView() {
super.loadView()
// initiate tabController the same way I did in the AppDelegate
UIApplication.shared.keyWindow?.rootViewController = tabController
}
Check the value "Is initial View Controller" for it.
This question already has an answer here:
Xcode 11 & iOS13, using UIKIT can't change background colour of UIViewController
(1 answer)
Closed 3 years ago.
I am trying to programmatically set the initial View controller but i keep getting this Error. Any solutions?
2019-11-07 11:47:43.975990+0000 RestaurantApp[16319:147412] [WindowScene] Failed to instantiate the default view controller for UIMainStoryboardFile 'Main' - perhaps the designated entry point is not set?
Here is the code that i have Written.
import UIKit
#UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
let window = UIWindow()
let locationService = LocationService()
let storyboard = UIStoryboard(name: "Main", bundle: nil) //refernce to our storyboard
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
//setiing the root view control on our window
switch locationService.status {
case .notDetermined, .denied, .restricted:
let LocationViewController =
storyboard.instantiateViewController (withIdentifier: "LocationViewController") as? LocationViewController
LocationViewController?.locationService = locationService
window.rootViewController = LocationViewController
default:
assertionFailure()
}
window.makeKeyAndVisible()
return true
}
}
Here is an Image of my storyboard
iOS 13 has moved the windows setup from AppDelegate to SceneDelegate to support the use of (possibly multiple) scenes rather than a single window. You now have to do the setup like this:
class SceneDelegate: UIResponder, UIWindowSceneDelegate {
var window: UIWindow?
let storyboard = UIStoryboard(name: "Main", bundle: nil)
func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
guard let windowScene = scene as? UIWindowScene else { return }
let vc = storyboard.instantiateViewController (withIdentifier: "Primary") as! ViewController
window = UIWindow(windowScene: windowScene)
window?.rootViewController = vc
window?.makeKeyAndVisible()
}
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
let storyboard = UIStoryboard.init(name: "Main", bundle: nil)
let homeView = storyboard.instantiateViewController(withIdentifier: "ViewController") as! ViewController
self.window?.rootViewController = homeView
return true
}
this works for me
This error happens due to a simple mistake in your storyboard, and it’s easy to fix. When your app starts, iOS needs to know precisely which view controller needs to be shown first – known as your default view controller.
If you accidentally deleted that view controller, or otherwise made it not the default, then you’ll see the error “Failed to instantiate the default view controller for UIMainStoryboardFile 'Main' - perhaps the designated entry point is not set?” when your app launches, along with a plain black screen.
To fix the problem, open your Main.storyboard file and find whichever view controller you want to be shown when your app first runs. When it’s selected, go to the attributes inspector and check the box marked “Is Initial View Controller”. You should see a right-facing arrow appear to the left of that view controller, showing that it’s your storyboard’s entry point.
Go back to storyboard and checkmark this to make the viewController you want your app to start off to,
When developing an app, if I only want to test one screen, say, the third tab of a tab view, how would I make the app navigate there on start up?
I think a good solution is use a UI test to automatically navigate to the correct place in the app. Pausing on a breakpoint at the end of the test leaves the app to be played with manually.
rootViewController of window property in AppDelegate will be the first view controller shown on screen. you can make it by programming or using storyboard
by programming:
if NavigationController is the rootViewController of your window, put your own viewController in the first place (index at 0) of NavigationController's viewControllers which is an array. it will be on screen by default.
customNavigationController.viewControllers = [yourViewController]
or simply set your viewController to the rootViewController to the window property in appDelegate
AppDelegate.swift:
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
window = UIWindow(frame: UIScreen.main.bounds)
// window?.rootViewController = CustomTabBarViewController()
// customViewController will show on screen by default.
window?.rootViewController = CustomViewController()
window?.makeKeyAndVisible()
return true
}
by interface builder:
check your viewControlelr's attributes inspector panel, and check "is Initial View Controller" option, then you can see a simple arrow attached to this view controller.
or:
add identifier to your viewController, and fetch it from storyBoard, then set it to the rootViewController of the window object in appDelegate
let testController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "testController") as! TestController
let appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.window?.rootViewController = testController
I have cloned a project in Swift however the project has all been done programmatically (without the use of interface builder). The app uses a Parse PFLogin and PFSign up.
I would like to use a UITabBarController (in interface builder) to manage transitions of the views. Below is the code for my didFinishLaunchingWithOptions in the AppDelegate:
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
setupParse()
setupLayer()
//* Show View Controller
controller = LoginViewController()
controller.layerClient = layerClient
// Register for push
self.registerApplicationForPushNotifications(application)
self.window!.rootViewController = UINavigationController(rootViewController: controller)
self.window!.backgroundColor = UIColor.whiteColor()
self.window!.makeKeyAndVisible()
return true
}
Is setting the root view controller the same as setting as initial view controller?
What would be the best way to change this code to set the UITabBarController shown in my interface builder as the root.
Any help would be much appreciated.
Thanks
Marc
You want to set the initial UIViewController from within the storyboard. You can do this by pointing the arrow at your desired view controller:
You can also do this from within the view controller's attribute inspector, by selecting the "Is Initial View Controller?" checkbox.
You can then remove the UIWindow code from the didFinishLaunchingWithOptions function.
I hope this is a simple question. I have not found anything in SO that seems to fit what I'm trying to do. I am working on my first ever project so much of this is still quite new to me. The code I have pasted is from a test project I'm using before I add code to my real one.
My initial VC is the EULA. When the user accepts, I want to change the initial VC to the log in view. In this test project, I have two views with an IBAction for a Bar Button Item that will segue the project from VC to VC2. I am trying to set up code to change the initial VC in the AppDelegate with
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
// Override point for customization after application launch.
let storyboard = UIStoryboard(name: "View Controller", bundle: NSBundle.mainBundle())
let licenseAccepted = ?
var vc: UIViewController?
if !licenseAccepted {
vc = storyboard.instantiateViewControllerWithIdentifier("View Controller2")
} else {
vc = storyboard.instantiateInitialViewController()
}
window = UIWindow(frame: UIScreen.mainScreen().bounds)
window?.rootViewController = vc
window?.makeKeyAndVisible()
return true
}
but this is not working. First, let licenseAccepted = ? is not correct. I found that in another set of code and I thought it might work, but no. Also, how do I set a var for if the user accepts the license in the AppDelegate? Should that be done in the initial VC, the second VC that will become the initial VC or somewhere else?
I am using Xcode 7.1 and Swift2 if that helps.
I may be way off base or I may be a keystroke or two away. I am just not getting my head around this. Your assistance will be appreciated.