Warning: Attempt to present * on * whose view is not in the window hierarchy - swift
IosSwiftHierarchyPresentviewcontrollerIos Problem Overview
I'm trying to present a ViewController
if there is any saved data in the data model. But I get the following error:
> Warning: Attempt to present * on *whose view is not in the window hierarchy"
Relevant code:
override func viewDidLoad() {
super.viewDidLoad()
loginButton.backgroundColor = UIColor.orangeColor()
var request = NSFetchRequest(entityName: "UserData")
request.returnsObjectsAsFaults = false
var appDel:AppDelegate = (UIApplication.sharedApplication().delegate as AppDelegate)
var context:NSManagedObjectContext = appDel.managedObjectContext!
var results:NSArray = context.executeFetchRequest(request, error: nil)!
if(results.count <= 0){
print("Inga resultat")
} else {
print("SWITCH VIEW PLOX")
let internVC = self.storyboard?.instantiateViewControllerWithIdentifier("internVC") as internViewController
self.presentViewController(internVC, animated: true, completion: nil)
}
}
I've tried different solutions found using Google without success.
Ios Solutions
Solution 1 - Ios
At this point in your code the view controller's view has only been created but not added to any view hierarchy. If you want to present from that view controller as soon as possible you should do it in viewDidAppear
to be safest.
Solution 2 - Ios
In objective c: This solved my problem when presenting viewcontroller on top of mpmovieplayer
- (UIViewController*) topMostController
{
UIViewController *topController = [UIApplication sharedApplication].keyWindow.rootViewController;
while (topController.presentedViewController) {
topController = topController.presentedViewController;
}
return topController;
}
Solution 3 - Ios
Swift 3
I had this keep coming up as a newbie and found that present loads modal views that can be dismissed but switching to root controller is best if you don't need to show a modal.
I was using this
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = storyboard?.instantiateViewController(withIdentifier: "MainAppStoryboard") as! TabbarController
present(vc, animated: false, completion: nil)
Using this instead with my tabController:
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let view = storyboard.instantiateViewController(withIdentifier: "MainAppStoryboard") as UIViewController
let appDelegate = UIApplication.shared.delegate as! AppDelegate
//show window
appDelegate.window?.rootViewController = view
Just adjust to a view controller if you need to switch between multiple storyboard screens.
Solution 4 - Ios
Swift 3.
Call this function to get the topmost view controller, then have that view controller present.
func topMostController() -> UIViewController {
var topController: UIViewController = UIApplication.shared.keyWindow!.rootViewController!
while (topController.presentedViewController != nil) {
topController = topController.presentedViewController!
}
return topController
}
Usage:
let topVC = topMostController()
let vcToPresent = self.storyboard!.instantiateViewController(withIdentifier: "YourVCStoryboardID") as! YourViewController
topVC.present(vcToPresent, animated: true, completion: nil)
Solution 5 - Ios
for SWIFT
func topMostController() -> UIViewController {
var topController: UIViewController = UIApplication.sharedApplication().keyWindow!.rootViewController!
while (topController.presentedViewController != nil) {
topController = topController.presentedViewController!
}
return topController
}
Solution 6 - Ios
You just need to perform a selector with a delay - (0 seconds works).
override func viewDidLoad() {
super.viewDidLoad()
perform(#selector(presentExampleController), with: nil, afterDelay: 0)
}
@objc private func presentExampleController() {
let exampleStoryboard = UIStoryboard(named: "example", bundle: nil)
let exampleVC = storyboard.instantiateViewController(withIdentifier: "ExampleVC") as! ExampleVC
present(exampleVC, animated: true)
}
Solution 7 - Ios
Swift 4
func topMostController() -> UIViewController {
var topController: UIViewController = UIApplication.shared.keyWindow!.rootViewController!
while (topController.presentedViewController != nil) {
topController = topController.presentedViewController!
}
return topController
}
Solution 8 - Ios
I was getting this error while was presenting controller after the user opens the deeplink.
I know this isn't the best solution, but if you are in short time frame here is a quick fix - just wrap your code in asyncAfter
:
DispatchQueue.main.asyncAfter(deadline: .now() + 0.7, execute: { [weak self] in
navigationController.present(signInCoordinator.baseController, animated: animated, completion: completion)
})
It will give time for your presenting controller to call viewDidAppear
.
Solution 9 - Ios
Use of main thread to present and dismiss view controller worked for me.
DispatchQueue.main.async { self.present(viewController, animated: true, completion: nil) }
Solution 10 - Ios
> For swift 3.0 and above
public static func getTopViewController() -> UIViewController?{
if var topController = UIApplication.shared.keyWindow?.rootViewController
{
while (topController.presentedViewController != nil)
{
topController = topController.presentedViewController!
}
return topController
}
return nil}
Solution 11 - Ios
let storyboard = UIStoryboard(name: "test", bundle: nil)
let vc = storyboard.instantiateViewController(withIdentifier: "teststoryboard") as UIViewController
UIApplication.shared.keyWindow?.rootViewController?.present(vc, animated: true, completion: nil)
This seemed to work to make sure it's the top most view.
I was getting an error > Warning: Attempt to present myapp.testController: 0x7fdd01703990 on myapp.testController: 0x7fdd01703690 whose view is not in the window hierarchy!
Hope this helps others with swift 3
Solution 12 - Ios
I have tried so many approches! the only useful thing is:
if var topController = UIApplication.shared.keyWindow?.rootViewController
{
while (topController.presentedViewController != nil)
{
topController = topController.presentedViewController!
}
}
Solution 13 - Ios
All implementation for topViewController here are not fully supporting cases when you have UINavigationController
or UITabBarController
, for those two you need a bit different handling:
For UITabBarController
and UINavigationController
you need a different implementation.
Here is code I'm using to get topMostViewController:
protocol TopUIViewController {
func topUIViewController() -> UIViewController?
}
extension UIWindow : TopUIViewController {
func topUIViewController() -> UIViewController? {
if let rootViewController = self.rootViewController {
return self.recursiveTopUIViewController(from: rootViewController)
}
return nil
}
private func recursiveTopUIViewController(from: UIViewController?) -> UIViewController? {
if let topVC = from?.topUIViewController() { return recursiveTopUIViewController(from: topVC) ?? from }
return from
}
}
extension UIViewController : TopUIViewController {
@objc open func topUIViewController() -> UIViewController? {
return self.presentedViewController
}
}
extension UINavigationController {
override open func topUIViewController() -> UIViewController? {
return self.visibleViewController
}
}
extension UITabBarController {
override open func topUIViewController() -> UIViewController? {
return self.selectedViewController ?? presentedViewController
}
}
Solution 14 - Ios
The previous answers relate to the situation where the view controller that should present a view 1) has not been added yet to the view hierarchy, or 2) is not the top view controller.
Another possibility is that an alert should be presented while another alert is already presented, and not yet dismissed.
Solution 15 - Ios
Swift Method, and supply a demo.
func topMostController() -> UIViewController {
var topController: UIViewController = UIApplication.sharedApplication().keyWindow!.rootViewController!
while (topController.presentedViewController != nil) {
topController = topController.presentedViewController!
}
return topController
}
func demo() {
let vc = ViewController()
let nav = UINavigationController.init(rootViewController: vc)
topMostController().present(nav, animated: true, completion: nil)
}
Solution 16 - Ios
Swift 5.1:
let storyboard = UIStoryboard.init(name: "Main", bundle: Bundle.main)
let mainViewController = storyboard.instantiateViewController(withIdentifier: "ID")
let appDeleg = UIApplication.shared.delegate as! AppDelegate
let root = appDeleg.window?.rootViewController as! UINavigationController
root.pushViewController(mainViewController, animated: true)
Solution 17 - Ios
Rather than finding top view controller, one can use
viewController.modalPresentationStyle = UIModalPresentationStyle.currentContext
Where viewController is the controller which you want to present This is useful when there are different kinds of views in hierarchy like TabBar, NavBar, though others seems to be correct but more sort of hackish
The other presentation style can be found on apple doc