Dismiss two UIViewController at once without animation

Question

I have a stack of UIViewControllers like A -> B -> C. I want to go back to controller A from C. I'm doing it with below code:

DispatchQueue.global(qos: .background).sync {
// Background Thread
DispatchQueue.main.async {
    self.presentingViewController?.presentingViewController?.dismiss(animated: false, completion: {
    })}
}

It works but controller B seen on screen although I set animated to false. How can I dismiss two UIViewControllers without showing the middle one (B)?

P.S: I can't just directly dismiss from root controller and also I can't use UINavigationController

I searched the community but can't find anything about the animation.

Dismiss more than one view controller simultaneously

This could be easily achieved by using `UINavigationController`-based navigation instead of presenting view controllers from another view controller. That way you could use `setViewControllers` method to push/pop several view controllers at once, but having only one animation — mag_zbc, Nov 29 '18 at 10:33
I think you can dismiss controller B when show Controller C. Can be solution for you? And then when you dismiss controller C you will be back to A. — Gkolunia, Nov 29 '18 at 10:39
let `A` dismiss the `B`, it will also dismiss the `C` in case if it is presented by `B`. — Ratul Sharker, Nov 29 '18 at 10:55
You can use protocol to communicate back to `A` from `C`, or use the `self.presentingViewController.presentingViewController` only if you are sure about that, you presented two level of hierarchy — Ratul Sharker, Nov 29 '18 at 10:59
@RatulSharker I'm already dismissing it with presentingViewController.presentingViewController — Emre Önder, Nov 29 '18 at 11:09
@EmreÖnder - do you *want* the dismissal of `C` to be animated or not? — DonMag, Nov 29 '18 at 15:12
I want to dismiss C with or without animation. Animation is not a problem. The problem is B is seen on screen when I dismiss C so I want direct dismiss from C -> A — Emre Önder, Nov 30 '18 at 06:23

score 2 · Answer 1 · answered Nov 29 '18 at 11:10

2

Try this.

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

Created a sample storyboard like this

The yellow view controller is type of ViewController and the button action is as follows

@IBAction func Pressed(_ sender: Any) {
    self.presentingViewController?.presentingViewController?.dismiss(animated: true, completion: nil)
}

Output

answered Nov 29 '18 at 11:10

Ratul Sharker

7,484
4
35
44

This looks working but I think because my controllers has lots of contents, It takes time. Btw, red one is also seen on your example – Emre Önder Nov 29 '18 at 13:08

Gkolunia · Answer 2 · 2018-11-29T14:15:32.633

I've created example for dismissing B controller before showing C controller. You can try it.

    let bController = ViewController()
    let cController = ViewController()

    aController.present(bController, animated: true) {

        DispatchQueue.main.asyncAfter(wallDeadline: .now()+2, execute: {

            let presentingVC = bController.presentingViewController

            bController.dismiss(animated: false, completion: {

                presentingVC?.present(cController, animated: true, completion: nil)

            })
        })

    }

But on my opinion solution with using navigation controller would be the best for the case. For example you can put just B controller into navigation controller -> present the navController onto A controller -> then show C inside the navController -> then dismiss from C controller whole navController -> And you will see A controller again. Think about the solution too.

Another solution

I've checked another solution. Here extension which should solve your problem.

extension UIViewController {

    func dissmissViewController(toViewController: UIViewController, animated flag: Bool, completion: (() -> Void)? = nil) {
        self.dismiss(animated: flag, completion: completion)
        self.view.window?.insertSubview(toViewController.view, at: 0)
        dissmissAllPresentedControllers(from: toViewController)
        if toViewController.presentedViewController != self {
            toViewController.presentedViewController?.dismiss(animated: false, completion: nil)
        }
    }

    private func dissmissAllPresentedControllers(from rootController: UIViewController) {
        if let controller = rootController.presentedViewController, controller != self {
            controller.view.isHidden = true
            dissmissAllPresentedControllers(from: controller)
        }
    }

}

Usage

let rootController = self.presentingViewController!.presentingViewController! //Pointer to controller which should be shown after you dismiss current controller
self.dissmissViewController(toViewController: rootController, animated: true)

// All previous controllers will be dismissed too, // but you will not see them because I hide them and add to window of current view.

But the solution I think may not cover all your cases. And potentially there can be a problem if your controllers are not shown on whole screen, all something like that, because when I simulate that transition I don't consider the fact, so you need to fit the extension maybe to your particular case.

Sorry, I don't wanna loose B on every time I open C. Sometimes user wants to go back to B — Emre Önder, Nov 29 '18 at 13:08
@EmreÖnder In the case only solution with navigation controller perfectly fits to your requirements. Which I described in my answer above. If you need I can make example for the case too. — Gkolunia, Nov 29 '18 at 13:12
Thank you for that but I can't use nav controller in my project now because It has lots of controllers and codes. This A, B, C is just an example. — Emre Önder, Nov 29 '18 at 13:15
I've got it. I have another thought, But it needs to be check, when i check it i will be back to you. — Gkolunia, Nov 29 '18 at 13:18
@EmreÖnder I've edited my answer with new solution for you. — Gkolunia, Nov 29 '18 at 14:13

Dismiss two UIViewController at once without animation

2 Answers2