Issue
I started taking a look on the Swift Programming Language, and somehow I am not able to correctly type the initialization of a UIViewController from a specific UIStoryboard.
In Objective-C I simply write:
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"StoryboardName" bundle:nil];
UIViewController *viewController = [storyboard instantiateViewControllerWithIdentifier:#"ViewControllerID"];
[self presentViewController:viewController animated:YES completion:nil];
Can anyone help me on how to achieve this on Swift?
This answer was last revised for Swift 5.4 and iOS 14.5 SDK.
It's all a matter of new syntax and slightly revised APIs. The underlying functionality of UIKit hasn't changed. This is true for a vast majority of iOS SDK frameworks.
let storyboard = UIStoryboard(name: "myStoryboardName", bundle: nil)
let vc = storyboard.instantiateViewController(withIdentifier: "myVCID")
self.present(vc, animated: true)
Make sure to set myVCID inside the storyboard, under "Storyboard ID."
For people using #akashivskyy's answer to instantiate UIViewController and are having the exception:
fatal error: use of unimplemented initializer 'init(coder:)' for class
Quick tip:
Manually implement required init?(coder aDecoder: NSCoder) at your destination UIViewController that you are trying to instantiate
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
If you need more description please refer to my answer here
This link has both the implementations:
Swift:
let viewController:UIViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier("ViewController") as UIViewController
self.presentViewController(viewController, animated: false, completion: nil)
Objective C
UIViewController *viewController = [[UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil] instantiateViewControllerWithIdentifier:#"ViewController"];
This link has code for initiating viewcontroller in the same storyboard
/*
Helper to Switch the View based on StoryBoard
#param StoryBoard ID as String
*/
func switchToViewController(identifier: String) {
let viewController = self.storyboard?.instantiateViewControllerWithIdentifier(identifier) as! UIViewController
self.navigationController?.setViewControllers([viewController], animated: false)
}
akashivskyy's answer works just fine! But, in case you have some trouble returning from the presented view controller, this alternative can be helpful. It worked for me!
Swift:
let storyboard = UIStoryboard(name: "MyStoryboardName", bundle: nil)
let vc = storyboard.instantiateViewControllerWithIdentifier("someViewController") as! UIViewController
// Alternative way to present the new view controller
self.navigationController?.showViewController(vc, sender: nil)
Obj-C:
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"MyStoryboardName" bundle:nil];
UIViewController *vc = [storyboard instantiateViewControllerWithIdentifier:#"someViewController"];
[self.navigationController showViewController:vc sender:nil];
Swift 4.2 updated code is
let storyboard = UIStoryboard(name: "StoryboardNameHere", bundle: nil)
let controller = storyboard.instantiateViewController(withIdentifier: "ViewControllerNameHere")
self.present(controller, animated: true, completion: nil)
// "Main" is name of .storybord file "
let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
// "MiniGameView" is the ID given to the ViewController in the interfacebuilder
// MiniGameViewController is the CLASS name of the ViewController.swift file acosiated to the ViewController
var setViewController = mainStoryboard.instantiateViewControllerWithIdentifier("MiniGameView") as MiniGameViewController
var rootViewController = self.window!.rootViewController
rootViewController?.presentViewController(setViewController, animated: false, completion: nil)
This worked fine for me when i put it in AppDelegate
If you want to present it modally, you should have something like bellow:
let vc = self.storyboard!.instantiateViewControllerWithIdentifier("YourViewControllerID")
self.showDetailViewController(vc as! YourViewControllerClassName, sender: self)
I would like to suggest a much cleaner way. This will be useful when we have multiple storyboards
1.Create a structure with all your storyboards
struct Storyboard {
static let main = "Main"
static let login = "login"
static let profile = "profile"
static let home = "home"
}
2. Create a UIStoryboard extension like this
extension UIStoryboard {
#nonobjc class var main: UIStoryboard {
return UIStoryboard(name: Storyboard.main, bundle: nil)
}
#nonobjc class var journey: UIStoryboard {
return UIStoryboard(name: Storyboard.login, bundle: nil)
}
#nonobjc class var quiz: UIStoryboard {
return UIStoryboard(name: Storyboard.profile, bundle: nil)
}
#nonobjc class var home: UIStoryboard {
return UIStoryboard(name: Storyboard.home, bundle: nil)
}
}
Give the storyboard identifier as the class name, and use the below code to instantiate
let loginVc = UIStoryboard.login.instantiateViewController(withIdentifier: "\(LoginViewController.self)") as! LoginViewController
No matter what I tried, it just wouldn't work for me - no errors, but no new view controller on my screen either. Don't know why, but wrapping it in timeout function finally made it work:
DispatchQueue.main.asyncAfter(deadline: .now() + 0.0) {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let controller = storyboard.instantiateViewController(withIdentifier: "TabletViewController")
self.present(controller, animated: true, completion: nil)
}
Swift 3
let settingStoryboard : UIStoryboard = UIStoryboard(name: "SettingViewController", bundle: nil)
let settingVC = settingStoryboard.instantiateViewController(withIdentifier: "SettingViewController") as! SettingViewController
self.present(settingVC, animated: true, completion: {
})
Swift 4:
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let yourVC: YourVC = storyboard.instantiateViewController(withIdentifier: "YourVC") as! YourVC
If you have a Viewcontroller not using any storyboard/Xib, you can push to this particular VC like below call :
let vcInstance : UIViewController = yourViewController()
self.present(vcInstance, animated: true, completion: nil)
I know it's an old thread, but I think the current solution (using hardcoded string identifier for given view controller) is very prone to errors.
I've created a build time script (which you can access here), which will create a compiler safe way for accessing and instantiating view controllers from all storyboard within the given project.
For example, view controller named vc1 in Main.storyboard will be instantiated like so:
let vc: UIViewController = R.storyboard.Main.vc1^ // where the '^' character initialize the controller
Swift 5
let vc = self.storyboard!.instantiateViewController(withIdentifier: "CVIdentifier")
self.present(vc, animated: true, completion: nil)
I created a library that will handle this much more easier with better syntax:
https://github.com/Jasperav/Storyboardable
Just change Storyboard.swift and let the ViewControllers conform to Storyboardable.
guard let vc = storyboard?.instantiateViewController(withIdentifier: "add") else { return }
vc.modalPresentationStyle = .fullScreen
present(vc, animated: true, completion: nil)
if let destinationVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "DestinationVC") as? DestinationVC{
let nav = self.navigationController
//presenting
nav?.present(destinationVC, animated: true, completion: {
})
//push
nav?.pushViewController(destinationVC, animated: true)
}
I use this helper:
struct Storyboard<T: UIViewController> {
static var storyboardName: String {
return String(describing: T.self)
}
static var viewController: T {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
guard let vc = storyboard.instantiateViewController(withIdentifier: Self.storyboardName) as? T else {
fatalError("Could not get controller from Storyboard: \(Self.storyboardName)")
}
return vc
}
}
Usage (Storyboard ID must match the UIViewController class name)
let myVC = Storyboard.viewController as MyViewController
I am facing very weird error unexpectedly found nil while unwrapping an optional value navigationcontroller.
I have two viewControllers which has main function is to scan bar code and sets value in textField on PreBarCodeViewController. Second viewController is the barcodeViewController which scan. According to perspective user either manually input value or scan to fetch bar code. When I go for manual input navigation controller works fine. But once I click for scan and gets value in a textField and press ok button it won't navigate. Even if I click cross button it gives me nil error.
Updated: included barcode viewcontroller open on button tap.
PreBarcodeViewController: two buttons Back and Accept
#IBAction func toBarcode(_ sender: Any) {
let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let newViewController = storyBoard.instantiateViewController(withIdentifier: "BarcodeViewController") as! BarcodeViewController
present(newViewController, animated: true, completion: nil)
}
#IBAction func onClickedBackArrow(_ sender: Any) {
self.navigationController!.popViewController(animated: true)
}
#IBAction func onClickedAccept(_ sender: Any) {
let value = textField.text ?? String(describing: txtValue)
bardelegate?.listFunc(listValue: value )
self.navigationController?.popViewController(animated: true)
}
BarcodeViewController: When I get the value post to back.
if url == decodedURL {
let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)
let newViewController = storyBoard.instantiateViewController(withIdentifier: "PreBarcodeViewController") as! PreBarcodeViewController
let str2 = String(url)
newViewController.txtValue = str2
present(newViewController, animated: true, completion: nil)
}
When you open with present() view controller then used the
dismiss()
method to back to previous screen.
popViewController()
only used when you navigate with navigation controller please check this.
I've gone through a tad amount of SO posts about this but none of them clearly state how to get this done in Swift 3.
Simply put, I need to close the current view that is displayed and open a new view controller. Such that the only view controller open would be the 2nd VC
This is the code I tried using, but when I try this the view controller gets closed without the rest of the code getting executed
//Close current VC
self.dismiss(animated: true, completion: nil)
//Open the new VC
let mainStoryboard: UIStoryboard = UIStoryboard(name:"Main",bundle:Bundle.main)
let secondViewController: SecondViewController = mainStoryboard.instantiateViewController(withIdentifier: "SecondViewController") as! SecondViewController
self.present(secondViewController, animated: true, completion: nil)
Can someone help me out? I just need a simple transition from 1st VC to 2nd VC and close the 1st VC.
The problem is, that "self" can not present the new ViewController since it is the ViewController that is getting dismissed.
You could try calling self.presentingViewController?.present(secondViewController, animated: true, completion: nil)
After spend full day i got a solution on Apple' developer website (on this link)
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let secondVC = storyboard.instantiateViewController(identifier: "second_view_controller")
secondVC.modalPresentationStyle = .fullScreen
secondVC.modalTransitionStyle = .crossDissolve
present(secondVC, animated: true, completion: nil)
If you presented that view controller from some view controller or it is the viewcontroller from navigation or tab viewcontroller, then try to get last visible view controller, code is in this link
Get the current displaying UIViewController on the screen in AppDelegate.m
or else use this code (I have copied from that link)
public extension UIWindow {
public var visibleViewController: UIViewController? {
return UIWindow.getVisibleViewControllerFrom(self.rootViewController)
}
public static func getVisibleViewControllerFrom(_ vc: UIViewController?) -> UIViewController? {
if let nc = vc as? UINavigationController {
return UIWindow.getVisibleViewControllerFrom(nc.visibleViewController)
} else if let tc = vc as? UITabBarController {
return UIWindow.getVisibleViewControllerFrom(tc.selectedViewController)
} else {
if let pvc = vc?.presentedViewController {
return UIWindow.getVisibleViewControllerFrom(pvc)
} else {
return vc
}
}
}
}
Then present your viewcontroller from that visibleViewController -
//Close current VC
self.dismiss(animated: true, completion: nil)
//Open the new VC
let mainStoryboard: UIStoryboard = UIStoryboard(name:"Main",bundle:Bundle.main)
let secondViewController: SecondViewController = mainStoryboard.instantiateViewController(withIdentifier: "SecondViewController") as! SecondViewController
window?.visibleViewController?.present(secondViewController, animated: true, completion: nil)
If your view controller is the root view controller, then set it to root view controller
if let delegate = UIApplication.shared.delegate as? AppDelegate {
delegate.window?.rootViewController = secondViewController
}
I am using this code for push SHOW and MODALLY programmatically in iOS Objective C.
And now want to know about Swift 3.
NewsDetailsViewController *vc = instantiateViewControllerWithIdentifier:#"NewsDetailsVCID"];
vc.newsObj = newsObj;
//--this(SHOW)
[self.navigationController pushViewController:vc animated:YES];
//-- or this(MODAL)
[self presentViewController:vc animated:YES completion:nil];
Push
do like
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = storyboard.instantiateViewControllerWithIdentifier("NewsDetailsVCID") as NewsDetailsViewController
vc.newsObj = newsObj
navigationController?.pushViewController(vc,
animated: true)
or safer
if let viewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "NewsDetailsVCID") as? NewsDetailsViewController {
viewController.newsObj = newsObj
if let navigator = navigationController {
navigator.pushViewController(viewController, animated: true)
}
}
present
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = self.storyboard?.instantiateViewControllerWithIdentifier("NewsDetailsVCID") as! NewsDetailsViewController
vc.newsObj = newsObj
present(vc!, animated: true, completion: nil)
or safer
if let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "NewsDetailsVCID") as? NewsDetailsViewController
{
vc.newsObj = newsObj
present(vc, animated: true, completion: nil)
}
With an elegant way.
Create an Navigatable protocol:
protocol Navigatable {
/// Storyboard name where this view controller exists.
static var storyboardName: String { get }
/// Storyboard Id of this view controller.
static var storyboardId: String { get }
/// Returns a new instance created from Storyboard identifiers.
static func instantiateFromStoryboard() -> Self
}
Create a default instantiate controller implementation:
/**
Extension of Navigatable protocol with default implementations.
*/
extension Navigatable {
static func instantiateFromStoryboard() -> Self {
let storyboard = UIStoryboard(name: self.storyboardName, bundle: nil)
guard
let viewController = storyboard
.instantiateViewController(withIdentifier: self.storyboardId) as? Self else {
fatalError("Cannot instantiate the controller.")
}
return viewController
}
}
Extends the UIViewController to push a view controller:
extension UIViewController {
/**
Pushes a view controller of the provided type.
- Parameter viewControllerType: Type of view controller to push.
- Parameter completion: Function to be executed on completion.
Contains the view controller that was pushed when successful and nil otherwise.
*/
func pushViewControllerOfType<T: Navigatable>(viewControllerType: T.Type, completion: (T) -> Void) {
let viewController = T.instantiateFromStoryboard()
if let vc = viewController as? UIViewController {
self.pushViewController(vc, animated: true)
}
completion(viewController)
}
/**
Pushes a view controller of the provided type.
- Parameter viewControllerType: Type of view controller to push.
*/
func pushViewControllerOfType<T: Navigatable>(viewControllerType: T.Type) {
self.pushViewControllerOfType(viewControllerType: viewControllerType) { _ in }
}
}
Then you can use the Navigatable protocol for a specific view controller.
class MySuperViewController {
override func viewDidLoad() {
...
}
// ...
}
extension MySuperViewController: Navigatable {
static var storyboardName: String {
return "Main"
}
static var storyboardId: String {
return "MySuperViewControllerId" // From your story board name Main
}
}
// Instantiate your controller
let vc = MySuperViewController.instantiateFromStoryboard()
// Or
//
// Push your view controller
// testViewController.swift
self.pushViewControllerOfType(viewControllerType: MySuperViewController)
//Create object of view controller
let obj = self.storyboard?.instantiateViewController(withIdentifier: "ViewControllerIdentifier”) as! ViewControllerName
//Push Controller
self.navigationController?.pushViewController(obj, animated: true)
//Present Controller
self.navigationController?.present(obj, animated: true, completion: nil)
I am trying to use this inside my function to present a view controller after a function runs, so included it inside
let window = UIWindow()
let rootViewController = window.rootViewController
let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())
let setViewController = mainStoryboard.instantiateViewControllerWithIdentifier("EmployeeTBCIdentifier")
rootViewController?.presentViewController(setViewController, animated: true, completion: nil)
It's not doing anything, it works if I use it inside viewDidLoad()
here's the main idea, and would it be possible to use completions according to this example,
func logInType(completion(Void1, Void2)->()) {
if login == employer{
void1
}else if login == employee{
void2
}
}
when using the function I want to return this
func logInType{(void1, void2) -> void in
void1 = self.presentview //I want to push view to another if this code executed
void2 = self.presentview //same idea
}
updated : code is working but it's not pushing to the viewcontroller identified.
dispatch_async(dispatch_get_main_queue()){
let window = UIWindow()
let rootViewController = window.rootViewController
let mainStoryboard: UIStoryboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())
let setViewController = mainStoryboard.instantiateViewControllerWithIdentifier("EmployeeTBCIdentifier")
rootViewController?.presentViewController(setViewController, animated: true, completion: nil)
}
Seems to me that there might be a problem in how you are getting the rootViewController. I think the let window = UIWindow() call is going to return a new UIWindow object instead of what you want which is the window that the root view controller (and your app) is associated with. Continuing this, rootViewController will be nil and your optional chain call rootViewController?.presentViewController(setViewController, animated: true, completion: nil) won't do anything. Use an explicit unwrap via rootViewController!.presentViewController(setViewController, animated: true, completion: nil) and you should see the error
To rectify, get the correct UIWindow another way, either from the UIAppDelegate or from another view controller using OtherViewController.view!.window!
Try using it like so:
dispatch_async(dispatch_get_main_queue())
{
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = storyboard.instantiateViewControllerWithIdentifier("mainView") as! MainViewController
self.presentViewController(vc, animated: true, completion: nil)
}