Swift viewWillAppear not being called after dismissing view controller

Question

I am presenting a view controller from a view controller called HomeController like so:

let viewController = self.storyboard?.instantiateViewController(withIdentifier: "LoginController") as! LoginController

let navigationController: UINavigationController = UINavigationController(rootViewController: viewController)

present(navigationController, animated: true, completion: nil)

In the presented view controller LoginController at some point gets dismissed:

self.dismiss(animated: true, completion: nil)

But when it comes back to HomeController it is not calling viewWillAppear, I really need to check on condition on HomeController when it comes back to it, So how can I call viewWillAppear when LoginController dismisses the view?

Where would I set that or find out what type? It’s just a plain old present call — user979331, Jun 28 '18 at 18:21
If the presentation is not over full screen or if the animation is custom, then the appearance methods are not called on the underlying controller. — Sulthan, Jun 28 '18 at 18:24

Kevinosaurio · Accepted Answer · 2018-06-28T18:46:41.657

46

You need to set the correct presentationStyle. If you want that your presentedController will be fullScreen and call it the previous viewWillAppear, then you can use ".fullScreen"

let viewController = self.storyboard?.instantiateViewController(withIdentifier: "LoginController") as! LoginController

let navigationController: UINavigationController = UINavigationController(rootViewController: viewController)

navigationController.modalPresentationStyle = .fullScreen

present(navigationController, animated: true, completion: nil)

edited Jun 28 '18 at 18:46

answered Jun 28 '18 at 18:21

Kevinosaurio

1,952
2
15
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1

I tried this viewWillAppear is not being called when dimissing LoginController – user979331 Jun 28 '18 at 18:44
1

@user979331 sorry my Bad is *.fullScreen* – Kevinosaurio Jun 28 '18 at 18:46
2

You can click on the segue in the storyboard and under the Attributes Inspector, change the Presentation to Full Screen. For me, it is easier than writing the code. – K. Law Mar 11 '19 at 14:08
1

I know this is an old question but still relevant to keep it fresh. I had a issue with not ALL my segues being fullscreen modal presentation. It was driving me crazy but it makes sense. All view controllers presented modally must be full screen otherwise view will appear will not be called at all. Even if you miss one, the last view when dismissed to root, will not call view will appear. – Julian Silvestri Apr 06 '20 at 20:13
Is there any way to call willAppear after dismiss viewController if use "PresentationStyle = .overCurrentContext" ? Because I need transparent model view so can not use modalPresentationStyle = .fullScreen. – Dipak Apr 22 '21 at 07:07
@Dipak you can use PresentationStyle = .currentContext – Kevinosaurio Apr 23 '21 at 01:28
@Kevinosaurio after using PresentationStyle = .currentContex, viewWillAppear get called but lost transparency. Transparency is my basic requirement so can not use currentContex – Dipak Apr 27 '21 at 10:06
I works. Setting by code helped me to check the solution, also you can change it from IB in the Navigation Controller > Attributes Inspector. – tontonCD Aug 11 '21 at 14:29

score 16 · Answer 2 · answered Feb 09 '22 at 18:13

16

If presented viewController is half screen then you will have to Call the viewWillAppear of presenting viewController manually in side presented view controller's viewWillDisappear. Add following code to your Presented view controller.

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    presentingViewController?.viewWillDisappear(true)
}    

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    presentingViewController?.viewWillAppear(true)
}

Note: you must have to call 'presentingViewController?.viewWillDisappear(true)' to get your Presenting view controllers viewWillAppear execute everytime.

answered Feb 09 '22 at 18:13

VIkas

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1
3

3

This is the correct solution. – Struki84 Apr 21 '22 at 16:39
OMG, I've been passing in the presenting VC as a delegate to the popover VC. Then using the delegate to call the needed functions in the presenting VC. fml. This is the solution. "presentingViewController". – Sean Mayes Nov 13 '22 at 20:25
Solution is not working. – Mihir Oza Nov 23 '22 at 17:08
This solution throws errors in the console and break animation in UINavigationControllers - see my solution here https://stackoverflow.com/a/74618304/158548 – Niall Mccormack Nov 29 '22 at 17:57
1

Now The viewDidAppear is stop working on other views. – Elad Mar 07 '23 at 12:57

score 9 · Answer 3 · answered Dec 02 '21 at 12:20

Changing presentation style to .fullScreen works but changes the appearance of the presented view Controller. If u want to avoid that u can override the viewWillDisappear method in the presented viewcontroller and inside it add presentingViewController?.viewWillAppear(true).

Example:

 class ViewControllerA: UIViewController {
 
      override func viewDidLoad() {
          super.viewDidLoad()
          
          //put the presenting action wherever you want

          let vc = ViewControllerB()
          navigationController.present(vc, animated: true)
      }

      override func viewWillAppear(_ animated: Bool) {
           super.viewWillAppear(animated) 
           //refresh Whatever 
      }
 }

 class ViewControllerB: UIViewController {
 
      override func viewDidLoad() {
          super.viewDidLoad()
      }

      override func viewWillDisappear(_ animated: Bool) {
          super.viewWillDisappear(animated)

          //this will call the viewWillAppear method from ViewControllerA  

          presentingViewController?.viewWillAppear(true)
      }
 }

It's also worth noting with this approach that if ViewControllerB presents ViewControllerC, then the viewWillDisappear() method is also called when ViewControllerC appears, which might not be desirable. — Derek Lee, Nov 04 '22 at 08:52
This solution throws errors in the console and break animation in UINavigationControllers - see my solution here https://stackoverflow.com/a/74618304/158548 — Niall Mccormack, Nov 29 '22 at 17:57

score 4 · Answer 4 · edited Nov 29 '22 at 18:13

None of these solutions seemed satisfactory, and indeed the solutions that suggested calling presentingViewController?.viewWillAppear(true) actually break animations in navigations controllers and throws warnings from UIKit in the console.

The correct way is to use the built in methods in UIKit, as suggested by the warnings! These will call all the respective methods viewWill/DidAppear in the presenting class.

Note I have an if statement checking if the modelPresentationStyle is equal to pageSheet as this is the value that recent releases of iOS set the default presentation style to. We do not want to interfere with other presentation styles as they may already call viewWill/DidAppear and it should not be called twice.

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

    // view lifecycle events are not passed down to the presentingViewController if in pageSheet style (and maybe others)
    if modalPresentationStyle == .pageSheet {
        presentingViewController?.beginAppearanceTransition(false, animated: animated)
    }
}

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

    // view lifecycle events are not passed down to the presentingViewController if in pageSheet style (and maybe others)
    if modalPresentationStyle == .pageSheet {
        presentingViewController?.endAppearanceTransition()
    }
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)

    // view lifecycle events are not passed down to the presentingViewController if in pageSheet style (and maybe others)
    if modalPresentationStyle == .pageSheet {
        presentingViewController?.beginAppearanceTransition(true, animated: animated)
    }
}

override func viewDidDisappear(_ animated: Bool) {
    super.viewDidDisappear(animated)

    // view lifecycle events are not passed down to the presentingViewController if in pageSheet style (and maybe others)
    if modalPresentationStyle == .pageSheet {
        presentingViewController?.endAppearanceTransition()
    }
}

`presentingViewController` in `viewDidDisappear` always nil. you may add `private weak var presentingViewControllerBeforeDisappear: UIViewController?`, and set `presentingViewControllerBeforeDisappear = presentingViewController` before `presentingViewController?.beginAppearanceTransition(true, animated: animated)` in `viewWillDisappear`, and then set `presentingViewControllerBeforeDisappear?.endAppearanceTransition()` in `viewDidDisappear` — Leo, Dec 01 '22 at 14:19
Thank you Leo for you comment it do solve the issue for the viewDidDisappear case. @Eric can you update the answer to include Leo fix? — Iosif, May 09 '23 at 07:06

score 3 · Answer 5 · answered Feb 19 '20 at 07:25

3

In iOS 13 , if you are presenting a view controller and when you are coming back viewWillAppear doesn't get called . I have changed it from present to push view controller and methods are getting called now .

answered Feb 19 '20 at 07:25

Sateesh Pasala

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8
15

Hi, could you please share more details? Where did you change it? – Smit May 07 '20 at 03:42
When u navigate from VC1 to VC2 , u must have written present view controller . just change it to push – Sateesh Pasala May 07 '20 at 04:55
1

one more way is to change the presentation style.: vc.modalPresentationStyle = UIModalPresentationFullScreen; – Sateesh Pasala May 07 '20 at 04:56
I think I understand you, but there is no push method, do I need to use some another protocol beside UIViewController for this? – Smit May 07 '20 at 05:00
How are u navigating to another view controller ? – Sateesh Pasala May 13 '20 at 11:41
@SateeshPasala if you navigate from VC1 to VC2 with modal presentation mode ? – iGhost Jun 08 '20 at 18:33
Then you have to set it to full screen mode. like this VC2.modalPresentationStyle = .fullScreen – Sateesh Pasala Jun 10 '20 at 08:56
3

i justed, but set .fullscreen is not working, viewwillapear did not called – famfamfam Jun 30 '20 at 09:13
same problem here, need a solution – famfamfam Jul 19 '20 at 08:59
I'm in iOS 13, and setting presentation to .fullscreen just works. You can have it from IB in the Navigation Controller > Attributes Inspector. The previous setting was .overFullScreen, now it works. – tontonCD Aug 11 '21 at 14:27

score 1 · Answer 6 · answered Aug 28 '22 at 19:12

Swift 5. Work for me. Maybe all forget about delegate.

First Controller

let calendarVC = CalendarVC()
calendarVC.delegate = self
calendarVC.modalTransitionStyle = .coverVertical
present(calendarVC, animated: true, completion: nil)

Present controller

Add Delegate ........

override func viewWillDisappear(_ animated: Bool) {
  super.viewWillDisappear(animated)
        delegate?.closeState()
 }

Work when swipe and dismiss button. Have a good day )

Swift viewWillAppear not being called after dismissing view controller

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