single function to dismiss all open view controllers

Question

I have an app which is a single view application. I have a navigation controller linked up to all child controllers from the root view controller.

In each child controller, I have a logout button. I'm wondering if I can have a single function I can call which will dismiss all the controllers which have been open along along the way, no matter which controller was currently open when the user presses logout?

My basic start:

func tryLogout(){
     self.dismissViewControllerAnimated(true, completion: nil)
     let navigationController = UINavigationController(rootViewController: UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier("LoginViewController") )
     self.presentViewController(navigationController, animated: true, completion: nil)
}

I am looking for the most memory efficient way of carrying out this task. I will put my logout function in a separate utils file, but then I can't use self. And I still have the issue of knowing which controllers to dismiss dynamically.

Update Pop to root view controller has been suggested. So my attempt is something like:

func tryLogout(ViewController : UIViewController){
     print("do something")
     dispatch_async(dispatch_get_main_queue(), {
         ViewController.navigationController?.popToRootViewControllerAnimated(true)
         return
     })
 }

Would this be the best way to achieve what I'm after?

You might just want to reinitialize your app's `UIWindow`'s `rootViewController` property. That will remove your entire view hierarchy (assuming you're not using other windows, which is rare). — Aaron Brager, Nov 04 '15 at 11:44
Are you presenting controllers or just pushing onto the nav stack? Where is the logout button? Can you just pop to root? What other clean up do you need to do? — Wain, Nov 04 '15 at 11:44
@Wain I have my controller linked up with segue identifiers in certain cases and I am presentingViewControllers with the defined identifier. Then there are some cases where I'm just doing basic segues i.e. a button's action, a table row's click event. The logout button is added to the nav bar as a left bar button item. No other clean up really. Reset a few Global Prefs just — user2363025, Nov 04 '15 at 11:51
@Aaron Brager sorry if this is a silly question, but what do you mean exactly about using other windows? — user2363025, Nov 04 '15 at 11:52
@user2363025 Very rarely an iOS app will have multiple UIWindows. You would know if you were making and managing them. — Aaron Brager, Nov 04 '15 at 12:07

score 194 · Accepted Answer · edited Dec 13 '19 at 11:18

194

You can call :

self.view.window!.rootViewController?.dismiss(animated: false, completion: nil)

Should dismiss all view controllers above the root view controller.

edited Dec 13 '19 at 11:18

Krunal Nagvadia

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answered Nov 04 '15 at 12:08

Liam

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Give this a go, let me know how it goes :), also assuming that self is the view controller that you are calling logout from. If it is called from somewhere else, you would need to pass the controller and replace self with the controller you would be calling logout from. – Liam Nov 04 '15 at 12:09
@Zorayr just change `false` to `true` for dismissAnimation, it should work: `self.view.window!.rootViewController?.dismissViewControllerAnimated(true, completion: nil)` – oyalhi Apr 19 '17 at 09:39
@Liam `self.view.window!.rootViewController?.dismissViewControllerAnimated(false, completion: nil) let mainStoryboardIpad : UIStoryboard = UIStoryboard(name: "Main", bundle: nil) let initialViewControlleripad : UIViewController = mainStoryboardIpad.instantiateViewControllerWithIdentifier("LogIn") as UIViewController self.appDelegate.window = UIWindow(frame: UIScreen.mainScreen().bounds) self.appDelegate.window?.rootViewController = initialViewControlleripad self.appDelegate.window?.makeKeyAndVisible()` This is my code – Coder Aug 03 '17 at 11:52
1

Suppose tested my app 5 times in that 3 times 'deinit {}' method is called sometime not. What is wrong with this ? And background my 'NSTimer' logic is working – Coder Aug 03 '17 at 11:55
3

Swift 3.0 syntax is `self.view.window!.rootViewController?.dismiss(animated: false, completion: nil)` – Pinwheeler Aug 07 '18 at 17:53

Bijender Singh Shekhawat · Answer 2 · 2020-04-23T11:56:16.247

39

Updated answer for Swift 4 and swift 5

UIApplication.shared.keyWindow?.rootViewController?.dismiss(animated: true, completion: nil)

and when you use navigationController

self.navigationController?.popToRootViewController(animated: true)

edited Apr 23 '20 at 11:56

answered Jul 22 '17 at 07:11

Bijender Singh Shekhawat

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score 30 · Answer 3 · answered May 14 '18 at 15:12

30

Swift 4:

To dismiss any unwanted residue Modal ViewControllers, I used this and worked well without retaining any navigation stack references.

UIApplication.shared.keyWindow?.rootViewController?.dismiss(animated: false, completion: nil)

self.view.window! did crash for my case possibly because its a Modal screen and had lost the reference to the window.

answered May 14 '18 at 15:12

Naishta

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Where to put it in completion block? – Nikhil Pandey Jul 07 '18 at 14:01

score 7 · Answer 4 · answered Apr 20 '17 at 20:49

7

Swift3

navigationController?.popToRootViewControllerAnimated(true)

answered Apr 20 '17 at 20:49

markhorrocks

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12

A good answer doesn't just post a line of code, it **explains** why it is an answer. – dfd Apr 20 '17 at 22:46
1

this will close all pushed view controllers at one, good answer – mgyky Oct 24 '17 at 08:24
2

This is a good answer, and doesn't need to be **explained** further. – Alec O May 11 '18 at 14:26

score 6 · Answer 5 · edited May 23 '17 at 12:26

6

Take a look at how unwind segues work. Its super simple, and lets you dismiss/pop to a certain viewcontroller in the heirarchy, even if it consists of a complex navigation (nested pushed and or presented view controllers), without much code.

Here's a very good answer (by smilebot) that shows how to use unwind segues to solve your problem https://stackoverflow.com/a/27463286/503527

edited May 23 '17 at 12:26

Community

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answered Aug 10 '16 at 16:06

Nitin Alabur

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score 4 · Answer 6 · answered Sep 10 '20 at 03:53

4

To dismiss all modal Views.

Swift 5


view.window?.rootViewController?.dismiss(animated: true, completion: nil)

answered Sep 10 '20 at 03:53

hectorsvill

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Bit shameless to copy paste the accepted answer as a new answer – J. Doe May 03 '21 at 18:29

score 0 · Answer 7 · edited Dec 02 '17 at 08:26

0

works for Swift 3.0 +

self.view.window!.rootViewController?.dismiss(animated: true, completion: nil)

edited Dec 02 '17 at 08:26

Vega

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answered Dec 02 '17 at 08:00

Pardeep Kumar

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score 0 · Answer 8 · answered Apr 26 '20 at 03:07

If you have a customed UITabbarController, then try dismiss top viewController in UITabbarController by:

class MainTabBarController: UITabBarController {

    func aFuncLikeLogout() {

        self.presentedViewController?.dismiss(animated: false, completion: nil)

        //......
    }

}

score -1 · Answer 9 · answered Apr 03 '19 at 05:25

-1

Swift Used this to jump directly on your ROOT Navigation controller.

self.navigationController?.popToRootViewController(animated: true)

answered Apr 03 '19 at 05:25

Rahul Panzade

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popToRoot... doesnt dismiss presented controllers as they aren't added to navigation stack. – Vlad E. Borovtsov Apr 08 '19 at 14:02

single function to dismiss all open view controllers

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