Dismiss two UIViewController at once without animation - ios

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

Answer 1

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

Answer 2

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.