Hi I'm kind of new to Swift and I can't figure this out. I am trying to create a sign out button that would take user to the login page. I used the following two methods but the first one doesn't do anything and the second one is throwing Fatal error: Unexpectedly found nil while implicitly unwrapping an Optional value and it refers to the code with the customButton:
//this one doesn't do anything
#objc func SignOut(){
let vc = self.storyboard?.instantiateViewController(identifier: "LoginViewController") as! LoginViewController
let appDelegate = UIApplication.shared.delegate
appDelegate?.window??.rootViewController = vc
}
//this one is throwing an error
let vc = CustomViewController()
self.present(vc, animated: true, completion: nil)
//the Fatal error refers to this code
override func viewDidLoad() {
super.viewDidLoad()
self.customButton.addTarget(self, action: #selector(customButtonPressed), for: .touchUpInside)
}
Also, I was wondering if AppDelegate is the right approach or if I should use SceneDelegate. Any help would be greatly appreciated.
Try to do this
#objc func SignOut(){
let vc = self.storyboard?.instantiateViewController(identifier: "LoginViewController") as! LoginViewController
self.view.window?.rootViewController = vc
}
let vc = self.storyboard?.instantiateViewController(identifier: "LoginViewController") as! LoginViewController
vc.modalPresentationStyle = .fullScreen
self.present(vc, animated: true, completion: nil)
Please make sure the identifier is matching the one inside storyboard for this viewController
I'm setting up a UISplitViewController programatically. This code appears to automatically segue to the detailViewController which is unwanted behaviour. Instead I would like it to present the masterViewController and let the user chose the detailViewController with didSelectRowAt IndexPath. Any help appreciated.
let splitViewController = UISplitViewController(nibName: nil, bundle: nil)
let masterNavigationController = UINavigationController(rootViewController: MasterViewController(nibName: nil, bundle: nil))
let detailNavigationController = UINavigationController(rootViewController: DetailViewController(nibName: nil, bundle: nil))
splitViewController.viewControllers = [masterNavigationController, detailNavigationController]
present(splitViewController, animated: true, completion: nil)
Implement the UISplitViewControllerDelegate method splitViewController(_:showDetail:sender:) (documentation here) to override the behaviour of your split vc.
In your specific case it should return true all the time except the time when the split vc is presented initially. In this case, you could set up a flag variable, e.g.
var isInitialState: Bool = true
then set it to false once the split vc has been presented completely – here I'm not sure when would be the best time, but I would guess
override func viewDidAppear(_ animated: Bool) {
[...]
isInitialState = false
[...]
}
I have problem... i have two ViewControllers and i use this code to pass from 1st VC to 2nd
let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let newViewController = storyBoard.instantiateViewController(withIdentifier: "EVSignInViewController") as! EVSignInViewController
self.present(newViewController, animated: true, completion: nil)
The problem is.. i want to display back button on 2nd VC. I already tried use Editor->Embed in-> Navigation controller on 1st VC. Also i use this
navigationController?.setNavigationBarHidden(false, animated: true)
navigationItem.backBarButtonItem = UIBarButtonItem(title:"", style:.plain, target:nil, action:nil)
Presenting a ViewController will present it modally over the top of your current one. It doesn't actually push it onto the navigation controllers navigation stack.
You either need to push the view controller instead
self.navigationController?.pushViewController(newViewController, animated: true)
or wrap it in a navigation controller and then present it
let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let newViewController = storyBoard.instantiateViewController(withIdentifier: "EVSignInViewController") as! EVSignInViewController
let navigation = UINavigationController(rootViewController: newViewController)
self.present(navigation, animated: true, completion: nil)
Use this method for present 2nd VC.
self.navigationController?.pushViewController(newViewController, animated: true)
instead of this
self.present(newViewController, animated: true, completion: nil)
You will get back button.
try this
self.navigationController?.navigationBar.isHidden = false
let storyboard = self.storyboard!
let storyCtrl = storyboard.instantiateViewControllerWithIdentifier("LoginTableViewController")
self.presentViewController(storyCtrl, animated: true, completion: { _ in })
I am getting this error : - fatal error: unexpectedly found nil while unwrapping an Optional value.
Swift 3.0 Use the following code to load controller from story board
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let viewController = storyboard.instantiateViewController(withIdentifier: "viewController")
self.presentViewController(viewController, animated: true, completion: { _ in })
Main = name of the storyboard
viewController = the name of the view controller identifier
I programatically have multiple View Controllers in an iOS Swift Project. I do not have the storyboards and would like to avoid them if possible. Is there a way to switch to another viewcontroller.swift file (We will call it view2.swift) and have it be part of a function that a button calls?I have tried the following:
let storyboard: UIStoryboard = UIStoryboard(name: "myTabBarName", bundle: nil)
let vc: UIViewController = storyboard.instantiateViewControllerWithIdentifier("myVCID") as UIViewController
self.presentViewController(vc, animated: true, completion: nil)
The above works with storyboards, but I want another view2.swift to be called. Can this be done?
Try this:
let vc = ViewController() //change this to your class name
self.presentViewController(vc, animated: true, completion: nil)
With Swift3:
self.present(vc, animated: true, completion: nil)
For those getting blank/black screens this code worked for me.
let vc = self.storyboard?.instantiateViewController(withIdentifier: myVCID) as! myVCName
self.present(vc, animated: true, completion: nil)
To set the "Identifier" to your VC just go to identity inspector for the VC in the storyboard. Set the 'Storyboard ID' to what ever you want to identifier to be. Look at the image below for reference.
For reference, because this question is one of the first Google result.
Breaking change in Swift 3:
The method presentViewController is replaced by the method present.
You can use it like the old one:
self.present(viewControllerToPresent, animated: true, completion: nil)
Example to open the camera:
let imagePicker = UIImagePickerController()
imagePicker.delegate = self
imagePicker.sourceType = UIImagePickerControllerSourceType.camera
imagePicker.allowsEditing = false
self.present(imagePicker, animated: true, completion: nil)
Swift 3 and Swift 4
let vc = self.storyboard?.instantiateViewController(withIdentifier: "idMyViewControllerName") as! MyViewControllerName
self.present(vc, animated: true, completion: nil)
For me, I had two views in two separate nav controllers. I had to use a combination of the above.
var vc = self.storyboard?.instantiateViewControllerWithIdentifier("WelcomeViewController") as! WelcomeViewController
var navigationController = UINavigationController(rootViewController: vc)
self.presentViewController(navigationController, animated: true, completion: nil)
Swift 3.x
let secondVC = self.storyboard?.instantiateViewController(withIdentifier: "VC-ID" as! yourViewController
let navigationVC = UINavigationController(rootViewController: secondVC)
self.present(navigationVC, animated: true, completion: nil)
Using Swift 2.1+
let vc = self.storyboard?.instantiateViewControllerWithIdentifier("settingsVC") as! SettingsViewController
self.presentViewController(vc, animated: true, completion: nil)
Solved the black screen by adding a navigation controller and setting the second view controller as rootVC.
let vc = ViewController()
var navigationController = UINavigationController(rootViewController: vc)
self.presentViewController(navigationController, animated: true, completion: nil
Just use this : Make sure using nibName otherwise preloaded views of xib will not show :
var vc : ViewController = ViewController(nibName: "ViewController", bundle: nil) //change this to your class name
self.presentViewController(vc, animated: true, completion: nil)
You don't need to instantiate the ViewController in Storyboard just to get present() ViewController to work. That's a hackish solution.
If you see a black/blank screen when presenting a VC, it might be because you're calling present() from viewDidLoad() in the First/RootViewController, but the first View isn't ready yet.
Call present() from viewDidAppear to fix this, i.e.:
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
let yourVC = YourViewController()
self.present(yourVC, animated: true, completion: nil)
}
Once any "View" has appeared in your App, you can start calling present() from viewDidLoad().
Using UINavigationController (as suggested in an answer) is another option, but it might be an overkill to solve this issue. You might end up complicating the user flow. Use the UINavigationController based solution only if you want to have a NavigatonBar or want to return to the previous view controller.
You can use below code :
var vc = self.storyboard?.instantiateViewControllerWithIdentifier("YourViewController") as! YourViewController;
vc.mode_Player = 1
self.presentViewController(vc, animated: true, completion: nil)
Another possibility is that you do not have the XIB included in your Build target (which is what happened to me).
This could happen if you have a different target for Dev, Test & Release Builds (which you should have anyway).
I had a similar issue but in my case, the solution was to dispatch the action as an async task in the main queue
DispatchQueue.main.async {
let vc = self.storyboard?.instantiateViewController(withIdentifier: myVCID) as! myVCName
self.present(vc, animated: true, completion: nil)
}
It's already answered. But adding one more thing while presenting a UIViewController, If anyone is trying to add UIModalPresentationStyle :
if directly presenting the UIViewController as fullScreen:
let viewController = UIViewController()
viewController.modalPresentationStyle = .fullScreen
self.present(viewController, animated: true)
If there is UINavigationController with root view controller as UIViewController:
let viewController = UIViewController()
let navigationController = UINavigationController(rootViewController: viewController)
navigationController.modalPresentationStyle = .fullScreen
self.present(navigationController, animated: true)
More helpful answers:
Presenting modal in iOS 13 fullscreen
You can use code:
if let vc = self.storyboard?.instantiateViewController(withIdentifier: "secondViewController") as? secondViewController {
let appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.window?.rootViewController = vc
}