Go back to previous view controller doesn't work - ios

My first view controller has a button, which triggers the #IBAction goTo2ndVc() which presents a second ViewController:
class FirstVC: UIViewController {
...
#IBAction func goTo2ndVc() {
let secondVc = SecondVC(label: "I am second vc.")
self.presentViewController(secondVc, animated: true, completion: nil)
}
When the button is pressed, the 2nd view controller is shown on screen. No problem.
In 2nd view controller, there is also a button which is used to go back to 1st view controller:
class SecondVC: UIViewController {
...
#IBAction func backToFirst(sender: AnyObject) {
print("go back ...")
self.navigationController?.popViewControllerAnimated(true)
}
}
I looked on internet, people suggest to use navigationController?.popViewControllerAnimated(true) to go back to previous controller. But when I press the go back button I can see the print message "go back ..." but the app doesn't go back to 1st view controller. WHY?

#IBAction func backToFirst(sender: AnyObject) {
print("go back ...")
self.dismissViewControllerAnimated(true, completion: nil)
}
In Swift 3
self.dismiss(animated: true, completion: nil)
you should not use navigation controller, because you didn't use it when you were adding the second view controller. that's why simply call dismissViewControllerAnimated method.
You have to use UINavigationController and its pop methods only when you add your view controllers via pushViewController method.
Familiarize yourself with the concept of navigation controller here: https://developer.apple.com/library/ios/documentation/WindowsViews/Conceptual/ViewControllerCatalog/Chapters/NavigationControllers.html

there
the issue is very simple..
self.presentViewController(secondVc, animated: true, completion: nil)
the code will present second view, you are not pushing it.
self.navigationController?.popViewControllerAnimated(true)
the popViewController will pop back to the previous view controller from where it is been pushed.
So, there are two ways you can achieve what you want
1)If you want to present viewController then you have to dismiss the view controller to show previous view controller with
self.dismissViewControllerAnimated(true, completion: nil)
2)If you want to use PopToVewcontroller, then you have to push you second view controller instead of presenting it with
self.navigatioVonroller?.pushViewController(secondVc, animated: true)

If you want to return to the previous view controller, you can simply add:
[self dismissViewControllerAnimated:YES completion:nil];
to the button action method.
If this is added on the nav view controller present on every screen, I see no reason why it shouldn't work as it would always dismiss the most recently presented view.

Related

How to dismiss 2 modal view controllers without weird animation [duplicate]

This question already has answers here:
Dismissing multiple modal view controllers at once?
(7 answers)
Closed 4 years ago.
I recreated the question and describe its essence more precisely.
I have two view controllers presented modally on Swift 4, without storyboard (can't use unwind) and without navigation controller
A presents B which presents C.
The reason why we don't use navigation controller, it's because we what simple animation from bottom to top and instead of breaking the standard animation from right to left, we decided to use present.
I would like to dismiss 2 view controllers and go from C to A.
Please, don't mark this question as duplicate before you read my question carefully. I found a tone of similar post, but neither solved my problem. Some of them Objective-C or some of the suggest to use:
self.presentingViewController?.presentingViewController?.dismiss(animated: true, completion: nil)
Or:
self.presentingViewController?.dismiss(animated: false, completion: nil)
self.presentingViewController?.dismiss(animated: true, completion: nil)
It's works, but it create weird animation. It's just delete C and animate dismiss for B:
Expected result:
Idea: you need to dismiss third controller with animation and after dismissing you need to dismiss second without animation. While third controller is being dismissed, second shouldn't be visible.
First, set Presentation style of second view controller to Over Current Context when you're presenting it (since we will need to hide its view when we will dismiss third controller)
let vc2 = VC2()
vc2.modalPresentationStyle = .overCurrentContext
present(vc2, animated: true)
continue with creating callbacks properties for willDismiss and didDismiss inside third controller. This callback will be called before and after you dismiss third controller
class VC3: UIViewController {
var willDismiss: (() -> Void)?
var didDismiss: (() -> Void)?
#IBAction func dismissButtonPressed(_ sender: UIButton) {
willDismiss?()
dismiss(animated: true) {
self.didDismiss?()
}
}
}
then in second view controller in the place where you present third view controller, set third controller's callback properties: declare what happens when third controller will dismiss: you need to hide view of second and then after dismissing third you need to dismiss second without animation (view can stay hidden since view controller will be deinitialized)
class VC2: UIViewController {
#objc func buttonPressed(_ sender: UIButton) {
var vc3 = VC3()
vc3.willDismiss = {
self.view.isHidden = true
}
vc3.didDismiss = {
self.dismiss(animated: false)
}
present(vc3, animated: true)
}
}
Anyway, second option is using UINavigationController and then just call its method popToViewController(_:animated:).
Create a snapshot from the currently visible view and add it as a subview to the first presented view controller. To find that you can simply "loop through" the presenting view controllers and dismiss from the initial one:
#IBAction func dismissViewControllers(_ sender: UIButton) {
var initialPresentingViewController = self.presentingViewController
while let previousPresentingViewController = initialPresentingViewController?.presentingViewController {
initialPresentingViewController = previousPresentingViewController
}
if let snapshot = view.snapshotView(afterScreenUpdates: true) {
initialPresentingViewController?.presentedViewController?.view.addSubview(snapshot)
}
initialPresentingViewController?.dismiss(animated: true)
}
This is the result with slow animations enabled for the dismissal:
https://www.dropbox.com/s/tjkthftuo9kqhsg/result.mov?dl=0
If you are not using a navigation controller and you want to dismiss all ViewControllers to show the root ViewController (assuming A is the root):
self.view.window?.rootViewController?.dismiss(animated: true, completion: nil)
Use this in button action method.
The current VC will dismiss when you dismiss the parent VC.
This will dismiss both VCs in single animation.
self.presentingViewController?.presentingViewController?.dismiss(animated: true, completion: nil)

How to get back from modal to main view controller

I'm totally newbie level with swift and having a question. so, I created a navigation controller for my modal and having my modal opened up from my first view controller with segue (Button2). The question is, how to get back to my first view controller from Modal View
You can use the dismiss method to dismiss a specific ViewController.
The question is how you want to dismiss the ViewController presented modally? With a button? Tap anywhere in the View? Tap on a little cross button?
For example if you have an UIButton to dismiss:
#IBAction func didTapClose(_ sender: UIButton) {
dismiss(animated: true, completion: nil)
}
If the segue is "present modally", you can dismiss the view controller through this line :
dismiss(animated: true, completion: nil);
Else If the segue is "show", you can dismiss the view controller through this line :
navigationController?.popViewController(animated: true);
In this case, be sure that you embedded your ViewController to a navigationController in your storyboard. If your ViewController is not embedded to a navigationController and you have used show segue, you should use dismiss(animated: true, completion: nil) to return to previous page.
Also there is other ways to return to previous pages (e.g., unwind segue)
Good luck.

navigationController:willShowViewController:animated: is not called after popToRootViewControllerAnimated in presented view controller

I have UINavigationController with several pushed view controllers.
UPD: Last pushed controller modally presents another controller.
Also, I have UINavigationControllerDelegate with some logic at navigationController:willShowViewController:animated:.
UPD: Navigation controller is its own delegate. Delegate is set in viewDidLoad method.
Question rises when I try to close all controllers programically from presented view controller:
// Close all controllers in navigation stack
presentingViewController?.navigationController?.popToRootViewController(animated: true)
// Close presented view controller
dismiss(animated: true, completion: nil)
Method navigationController:willShowViewController:animated: is not called. But it is called when I do the same without presented controller (thanks to #donmag for example project where it works).
Searched SO for answers or similar questions, but found nothing, any thoughts?
In your "presenting" VC, you want to implement a delegate/protocol pattern so your "presented" VC can call back and perform the dismiss and popToRoot...
// protocol for the presented VC to "call back" to the presenting VC
protocol dismissAndPopToRootProtocol {
func dismissAndPopToRoot(_ animated: Bool)
}
// in the presenting VC
#IBAction func presentTapped(_ sender: Any) {
if let vc = storyboard?.instantiateViewController(withIdentifier: "presentMeVC") as? PresentMeViewController {
// Assign the delegate when instantiating and presenting the VC
vc.dapDelegate = self
present(vc, animated: true, completion: nil)
}
}
func dismissAndPopToRoot(_ animated: Bool) -> Void {
// this will dismiss the presented VC and then pop to root on the NavVC stack
dismiss(animated: animated, completion: {
self.navigationController?.popToRootViewController(animated: animated)
})
}
// in the presented VC
var dapDelegate: dismissAndPopToRootProtocol?
#IBAction func dismissTapped(_ sender: Any) {
// delegate/protocol pattern - pass true or false for dismiss/pop animation
dapDelegate?.dismissAndPopToRoot(false)
}
Here's a full demo project: https://github.com/DonMag/CustomNavController
From documentation:
popToRootViewControllerAnimated:
Pops all the view controllers on the stack except the root view controller and updates the display.
popViewControllerAnimated:
Pops the top view controller from the navigation stack and updates the display.
So seems like in order to get navigationController:willShowViewController:animated: called every time you have to do subsequent popViewControllerAnimated:, because the display got updated each time after you pop a new controller. When you pop to root view controller, update display is called only once.

Navigation pushViewController is not working

i have login view controller. when usersingin i' showing popup for that i
refereed
https://www.youtube.com/watch?v=S5i8n_bqblE i can achieved that.
popup had button when i click the button navigation to next view controller
but its now working when i am clicking that action is performing but its not navigating to next view controller wher i did mistake
Singin
class DigitalGateViewController: NANavigationViewController
{
#IBAction func singin(_ sender: UIButton)
{
let lv = NAViewPresenter().activityVC()
self.present(lv, animated: true)
}
}
this is popupviewcontroller
class ActivityViewController: NANavigationViewController {
#IBAction func okbuttonclick() {
let dv = NAViewPresenter().myGuestListVC()
// self.navigationController?.pushViewController(dv, animated: true)
}
}
its not push to textview controller in swift
When you present a view controller, its presented modally and is not pushed onto the previous navigation controller's stack. Hence, you tried to call self.navigationController?.pushViewController(), it doesn't work, because self i.e. NAViewPresenter().myGuestListVC() isn't embedded in a navigation Controller.
If you want to push the new VC onto the previous stack, you will have to dismiss the presented pop up and then push. The easiest way to do this is to use a delegate method.
Edit:
if you want to create a new navigationController, you can do something like this :
let navController = UINavigationController(rootViewController: NAViewPresenter().myGuestListVC())
present(navController, animated: true)
After presenting the navController, you can use self.navigationController.push method henceforth.
The reason why its not pushing because you are presenting it modally not pushing on the navigation stack and so it wont have any navigationController. If you want to push from your modal popup, you can access the property presentingViewController on your modal object and try to push it on navigationController from there.
self.presentingViewController?.navigationController?.pushViewController(myVC, animated: true)
dismiss(animated: true, completion: nil)

ios swift - dismiss root view controller of navigation controller

I'm opening a navigation controller from a button click of my main view controller.
I programatically created a left bar button item on the navigation controller which I want to dismiss the nav controller and go back to my main controller.
I'm essentially going back on the root view controller of the navigation controller.
I've tried
navigationController?.dismissViewControllerAnimated(true, completion: nil)
and
self.dismissViewControllerAnimated(true, completion: nil)
and get an NSException on both.
Please advise.
Swift 3:
self.view.window!.rootViewController?.dismiss(animated: false, completion: nil)
It will dismiss all the presented view controllers and remain root view controller.
If you are pushing your ViewController, you should use pop to remove that ViewController from Navigation Stack and land on the previous ViewController. Try this...
self.navigationController?.popViewControllerAnimated(true);
SWIFT 3
_ = navigationController?.popViewController(animated: true);
dismissViewController works when you are showing a viewController using presentViewController, that maybe the root view controller of a navigation stack, or a stand alone view controller.
self.presentingViewController?.presentingViewController?.dismissViewControllerAnimated(true, completion: nil)
Try this :)
A year later.. The exception indicates that there is something wrong with the selector that you provide to the action param, when adding the left bar button.
Something like this should work:
creating bar button item:
let backBarButton = UIBarButtonItem.init(barButtonSystemItem: UIBarButtonSystemItem.stop, target: self, action: #selector(dismissView))
dismiss root view controller:
func dismissView() {
self.dismiss(animated: true, completion: nil)
}
Apple Dev already provides very simple code which is
self.navigationController?.popToRootViewController(animated: false)

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