For my requirement, I have to go back to my rootviewcontroller (tabbar) but It have many page present on it.
example flow
my tabbar (have 4 tabs each tab has own navigation ) -> push(vc1) -> present nav(vc2) -> push vc3 -> present nav(vc4)
If I want to close all viewcontroller ( vc1 - vc4 ) How to dismiss them by one function ?
You can use UIViewController.dismiss(animated:completion:) call on the base view controller that started presentation from tab bar (root level).
If you present several view controllers in succession, thus building a stack of presented view controllers, calling this method on a view controller lower in the stack dismisses its immediate child view controller and all view controllers above that child on the stack. When this happens, only the top-most view is dismissed in an animated fashion; any intermediate view controllers are simply removed from the stack. The top-most view is dismissed using its modal transition style, which may differ from the styles used by other view controllers lower in the stack.
Given this hierarchy
my tabbar (have 4 tabs each tab has own navigation ) -> push(vc1) -> present nav(vc2) -> push vc3 -> present nav(vc4)
You can walk back the presentation hierarchy like following -
let vc4Presenter = vc4.navigationController?.presentingViewController
let vc2NavCtrl = (vc4Presenter as? UINavigationController) ?? vc4Presenter?.navigationController
let vc2Presenter = vc2NavCtrl?.presentingViewController
let vc1NavCtrl = (vc2Presenter as? UINavigationController) ?? vc2Presenter?.navigationController
vc2Presenter?.dismiss(animated: true, completion: {
vc1NavCtrl?.popToRootViewController(animated: false)
})
Above is merely an example of how you can find the correct view controller instance to call dismiss on in the view hierarchy. This is definitely not well suited for dynamic number of presentation layers.
You can -
Write this in a recursive way (so that it keeps looking for presentingViewController until it finds nil for the root level).
Have a convenient reference to tab bar controller throughout the app and call dismiss on it's currently selected view controller (tab).
If you want go directly to first viewController:
self.popToRootViewController(animated: true)
If you want to see how it is going away one by one
#objc func buttonPressed() {
let viewControllers: [UIViewController] = self.viewControllers
for aViewController in viewControllers {
self.popViewController(animated: true)
}
self.popToRootViewController(animated: true)
}
Related
I'm new with IOS and Swift so don't judge if solution is easy.
I have three ViewControllers like A,B and C.
I started from A -> NavigationController -> B -> NavigationController -> C
In specific situation I need to come back from C to A without seeing B. Is any way to do this?
Maybe changing the parent navigationController? Maybe I can print stack with every current view? - it will be really helpful.
I tried dismiss C and B view one by one and it work's but then we can see B view for a moment - so it's not a solution for me.
P.s : I'm using Modal kind to switch between controllers.
enter image description here
If A is always the first view controller, you can just do :
viewcontrollerC.navigationController?.popToRootViewController(animated: true)
This methods pop the stack to the first view controller, without displaying intermediates ones
If A is not the first viewController, you can do :
viewcontrollerC.navigationController?. popToViewController(viewControllerA, animated: true)
If you don't have a reference to viewControllerA, search it in the stack :
let viewControllerA: UIViewController?
for (let vc in (self.navigationController?.viewControllers ?? [])) {
//adust the test to find the appropriate controller
if vc.isKindOf(ViewControllerAClass.self) {
viewControllerA = vc
break
}
}
if let viewControllerA = viewControllerA {
self.navigationController?.popToViewController(viewControllerA, animated: true)
}
source : https://developer.apple.com/documentation/uikit/uinavigationcontroller/1621871-poptoviewcontroller
There are 2 ways you can achieve this. The simple to implement is in View Controller C you can, on in the specific situation, invoke following function:
navigationController?.popToRootViewController(animated: true)
This will pop all the navigational view hierarchy and take you back to the root i.e. the first view controller.
Second approach is to define unwind method in the view controller you want to go back to. In view controller when you start typing unwind, in Xcode 10 you will get autocomplete to add this Swift Unwind Segue Method.
#IBAction func unwindToA(_ unwindSegue: UIStoryboardSegue) {
let sourceViewController = unwindSegue.source
// Use data from the view controller which initiated the unwind segue
}
In this particular question let us say you added this method in View Controller A as you want to go back to it. I assume you have a button on View Controller C to go back to A. Controll+Drag from the button to the Exit symbol of the view controller A. The unwindToA method will automatically pop-up. Connect to it and you are done. When the user presses this button it will go back 2 navigation controllers to A.
Note: By this method you can go back to any navigation controller on the Navigation stack and it is not limited to root view controller alone. Below I am addition picture showing the exit on a view controller.
I want a my app can go to a first view controller when every time users want it.
So I want to create a function to dismiss all the view controllers, regardless of whether it is pushed in navigation controllers or presented modally or opened anything methods.
I tried various ways, but I failed to dismiss all the view controllers certainly.
Is there an easy way?
Try This :
self.view.window?.rootViewController?.dismiss(animated: true, completion: nil)
it should dismiss all view controllers above the root view controller.
If that doesn't work than you can manually do that by running a while loop like this.
func dismissViewControllers() {
guard let vc = self.presentingViewController else { return }
while (vc.presentingViewController != nil) {
vc.dismiss(animated: true, completion: nil)
}
}
It would dismiss all viewControllers until it has a presentingController.
Edit : if you want to dismiss/pop pushed ViewControllers you can use
self.navigationController?.popToRootViewController(animated: true)
Hope it helps.
If you are using Navigation you can use first one
or if you are presenting modally you can second one:
For Navigation
self.navigationController?.popToRootViewController(animated: true)
For Presenting modally
self.view.window!.rootViewController?.dismissViewControllerAnimated(false, completion: nil)
Hello everyone here is the answer for Swift-4.
To go back to root view controller, you can simply call a line of code and your work will be done.
self.view.window?.rootViewController?.dismiss(animated: true, completion: nil)
And if you have the splash screen and after that the login screen and you want to go to login screen you can simply append presentedviewcontroller in the above code.
self.view.window?.rootViewController?.presentedViewController!.dismiss(animated: true, completion: nil)
Simply ask your rootViewController to dismiss any ViewController if presenting.
if let appDelegate = UIApplication.shared.delegate as? AppDelegate {
appDelegate.window?.rootViewController?.dismiss(animated: true, completion: nil)
(appDelegate.window?.rootViewController as? UINavigationController)?.popToRootViewController(animated: true)
}
The strategy to go back to your initial view controller could vary depending on your view controllers are stacked.
There could be multiple scenarios and depending on your situation, you can decide which approach is the best.
Scenario 1
Navigation controller is set as the root view controller
Navigation controller sets View Controller A as the root
Navigation controller pushes View Controller B
Navigation controller pushes View Controller C
This is a straightforward scenario where navigationController?.popToRootViewController(animated:true) is going to work from any view controller and return you back to View Controller A
Scenario 2
Navigation controller is set as the root view controller
Navigation controller sets View Controller A as the root
View Controller A presents View Controller B
View Controller B presents View Controller C
This scenario can be solved by the answers above
self?.view.window?.rootViewController.dismiss(animated: true) and will bring you back to View Controller A
Scenario 3
Navigation controller 1 is set as the root view controller
Navigation controller 1 sets View Controller A as the root
Navigation controller 1 pushes View Controller B
View Controller B presents Navigation Controller 2
Navigation Controller 2 sets View Controller D as the root
Navigation controller 2 pushes View Controller E
Now imagine that you need to go from View Controller E all the way back to A
Using the 2 answers above will not solve your problem this time as popping to root cannot happen if the navigation controller is not on the screen.
You might try to add timers and listeners for dismissing of view controllers and then popping which can work, I think there was an answer like this above with a function dismissPopAllViewViewControllers - I notice this leads to unusual behavior and with this warning Unbalanced calls to begin/end appearance transitions for
I believe what you can do to solve such scenarios is to
start by presenting your modal views controllers from the navigation controller itself
now you have better control to do what you want
So I would change the above to this architecture first:
Navigation controller 1 is set as the root view controller (same)
Navigation controller 1 sets View Controller A as the root (same)
Navigation controller 1 pushes View Controller B (same)
Navigation controller 1 presents Navigation Controller 2 (change)
Navigation Controller 2 sets View Controller D as the root (same)
Navigation controller 2 pushes View Controller E (same)
Now from View Controller E, if you add this:
let rootViewController = self?.view.window?.rootViewController as? UINavigationController
rootViewController?.setViewControllers([rootViewController!.viewControllers.first!],
animated: false)
rootViewController?.dismiss(animated: true, completion: nil)
you will be transported all the way back to View Controller A without any warnings
You can adjust this based on your requirements but this is the concept on how you can reset a complex view controller hierarchy.
Use this code for dismiss presented viewcontrollers and pop to navigation rootviewcontroller swift 4
// MARK:- Dismiss and Pop ViewControllers
func dismissPopAllViewViewControllers() {
if let appDelegate = UIApplication.shared.delegate as? AppDelegate {
appDelegate.window?.rootViewController?.dismiss(animated: true, completion: nil)
(appDelegate.window?.rootViewController as? UINavigationController)?.popToRootViewController(animated: true)
}
}
Swift 5.4:
self.navigationController?.popToRootViewController(animated: true)
Pops all the view controllers on the stack except the root view controller and updates the display.
func popToRootViewController(animated: Bool)
But if you want to go to specific controller just use the below function.
func popToViewController(UIViewController, animated: Bool)
Pops view controllers until the specified view controller is at the top of the navigation stack.
To achieve what you want, modify your navigation stack, then do popViewController.
let allControllers = NSMutableArray(array: navigationController!.viewControllers)
let vcCount = allControllers.count
for _ in 0 ..< vcCount - 2 {
allControllers.removeObject(at: 1)
}
// now, allControllers[0] is root VC, allControllers[1] is presently displayed VC. write back to nav stack
navigationController!.setViewControllers(allControllers as [AnyObject] as! [UIViewController], animated: false)
// then pop root VC
navigationController!.popViewController(animated: true)
See this for the way to further manipulate the navigation stack. If your topmost VC is modal, dismiss it first before the code above.
Create an Unwind Segue (You can find it at https://developer.apple.com/library/archive/featuredarticles/ViewControllerPGforiPhoneOS/UsingSegues.html copyright of Apple Inc.)
Unwind segues let you dismiss view controllers that have been
presented. You create unwind segues in Interface Builder by linking a
button or other suitable object to the Exit object of the current view
controller. When the user taps the button or interacts with the
appropriate object, UIKit searches the view controller hierarchy for
an object capable of handling the unwind segue. It then dismisses the
current view controller and any intermediate view controllers to
reveal the target of the unwind segue.
To create an unwind segue
Choose the view controller that should appear onscreen at the end of an unwind segue.
Define an unwind action method on the view controller you chose.
The Swift syntax for this method is as follows:
#IBAction func myUnwindAction(unwindSegue: UIStoryboardSegue)
The Objective-C syntax for this method is as follows:
- (IBAction)myUnwindAction:(UIStoryboardSegue*)unwindSegue
3. Navigate to the view controller that initiates the unwind action.
Control-click the button (or other object) that should initiate the unwind segue. This element should be in the view controller you want to dismiss.
Drag to the Exit object at the top of the view controller scene.
https://developer.apple.com/library/archive/featuredarticles/ViewControllerPGforiPhoneOS/Art/segue_unwind_linking_2x.png
Select your unwind action method from the relationship panel.
You must define an unwind action method in one of your view controllers before trying to create the corresponding unwind segue in Interface Builder. The presence of that method is required and tells Interface Builder that there is a valid target for the unwind segue.
In case anyone looking for an Objective-C implementation of the question's answer,
[self.view.window.rootViewController dismissViewControllerAnimated:true completion:nil];
func dismiss_all(view: UIView){
view.window!.rootViewController?.dismiss(animated: true, completion: nil)
}
May be what you are looking for is unwind segue.
Unwind segues give you a way to "unwind" the navigation stack back
through push, modal, popover, and other types of segues. You use
unwind segues to "go back" one or more steps in your navigation
hierarchy.
Link to documentation:
https://developer.apple.com/library/archive/technotes/tn2298/_index.html
The best and prefered way to do this is to create an unwind segue. Just follow this documentation https://developer.apple.com/library/archive/featuredarticles/ViewControllerPGforiPhoneOS/UsingSegues.html. It can de done in code or through the interface builder.
This question already has answers here:
Dismissing modal view controller stack
(3 answers)
Closed 5 years ago.
I am presenting a view controller with a presented view controller.
let viewController = self.getResponseViewController(r: r)
if let presented = self.presentedViewController {
presented.present(viewController, animated: true)
} else {
self.present(viewController, animated: true)
}
In the top level view controller, I have the following code...
presentingViewController?.presentingViewController?.dismiss(animated: true)
This works ok apart from the fact that the top level view controller immediately disappears and it's the first presented view controller that is animated out.
If I merely do...
dismiss(animated: true)
... then only the top most view controller is dismissed, leaving the first presented controller still in place.
How can I have the top level view controller animate out to reveal the root view controller, whilst showing no sign of the first presented view controller?
Basically, I just need to be able to stack two levels deep.
So A presented B and B is now presenting C.The easiest way to go to A, also as we don't want to see B exit, is to keep a reference to A and say dismiss or Pop to root on it from anywhere in C.OrDismiss C and in completion handler dismiss B
I am currently implementing the XLPagerTabStrip (https://github.com/xmartlabs/XLPagerTabStrip) which effectively creates a tab bar at the top of the view controller. I want to be able to segue to a new view controller from one of the tabbed controllers and be able to use the navigation bar to move backwards (or a custom version of the navigation bar if this isn't possible).
XLPagerTabStrip provides the moveToViewController and moveToViewControllerAtIndex functions to navigate between child view controllers, but this method doesn't allow use of a navigation bar to go backwards.
Conceptually XLPagerTabStrip is a collection of view controllers declared and initialized during the XLPagerTabStrip model creation.
It has virtually no sense to use a UINavigationController if you already have all the viewcontrollers available.
You can create a global var previousIndex to store the previous viewController index and allow users to go back by using canonical methods:
func moveToViewControllerAtIndex(index: Int)
func moveToViewControllerAtIndex(index: Int, animated: Bool)
func moveToViewController(viewController: UIViewController)
func moveToViewController(viewController: UIViewController, animated: Bool)
About a new viewController, suppose you have 4 viewControllers that built your container (XLPagerTabStrip) named for example z1, z2, z3 e z4.
You can embed to z4 a UINavigationController (so it have the z4 controller as rootViewController) and start to push or pop your external views. When you want to return to your z4 you can do popToRootViewControllerAnimated to your UINavigationController
When you are go back to z4 , here you can handle your global var previousIndex to moving inside XLPagerTabStrip.
I'm not familiar with XLPagerTabStrip, but I had a similar problem recently and the solution was to use an unwind segue to go back to the previous view controller. It's pretty trivial to implement so probably worth a try.
To navigate back to your previous view tab controller, you had initially navigated from;
Embed your new view controller, from which you wish to navigate
away from in a navigation bar
Connect it's Navigation Bar Button to the Parent view containing the
tab bar by dragging a segue between the 2 views
Create a global variable in App delegate to store current index
which you will use in the Parent view to determine what tab view
controller to be shown
var previousIndex: Int = 0 //0 being a random tab index I have chosen
In your new view controller's (the one you wish to segue from)
viewdidload function, create an instance of your global variable as
shown below and assign a value to represent a representative index
of the child tab bar view controller which houses it.
//Global variable instance to set tab index on segue
let appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.previousIndex = 2
You can write this for as many child-tab connected views as you wish, remembering to set the appropriate child-tab index you wish to segue back to
Now, create a class property to reference your global variable and a function in your Parent view as shown below
let appDelegatefetch = UIApplication.shared.delegate as! AppDelegate
The function
func moveToViewControllerAtIndex(){
if (appDelegatefetch.previousIndex == 1){
self.moveToViewControllerAtIndex((self.appDelegatefetch.previousIndex), animated: false)
} else if (appDelegatefetch.previousIndex == 2){
self.moveToViewControllerAtIndex((self.appDelegatefetch.previousIndex), animated: false)
}
}
You may now call this function in the Parent View Controller's viewDidLoad, as shown below.
moveToViewControllerAtIndex()
Run your project and that's it.
I'm currently designing an application that has a funnel flow and a dashboard flow. I'd like the funnel flow to be cleared from memory on completion:
So if it goes
1) if new user start funnel -> 2) funnel screens 1-5 -> 3) funnel complete screen
I'd like to transition to dashboard screen which is not yet on the stack (it's not my head controller in this case). How can I clear the 6 screens above from memory when I transition to dashboard - basically setting a new navigation root and clearing the rest? An unwind segue doesn't appear to be able to set a new root destination.
If you only want to clear the navigation stack, and push a new view on top of it, there is an even simpler solution.
Let's suppose you already (programmatically) assigned a navigation controller, e.g. in a viewDidLoad() function, like:
let navController = UINavigationController( rootViewController: YourRootController )
view.addSubview( navController.view )
addChildViewController( navController )
navController.didMoveToParentViewController( self )
YourRootController acts as the stacks's root (the bottom of the stack).
To push other controllers on top of the stack (your funnel controllers), simply use navController.pushViewController( yourControllerInstance!, animated: false ).
If you want to clear the stack after completion of the funnel, just call:
navController.popToRootViewControllerAnimated( false )
This function removes all views (besides the root controller) from your stack.
So I ended up having to do it programmatically by popping back to the first controller and then replacing from the funnel head to the dashboard head:
func bookingCompleteAcknowledged(){
//remove the popup controller
dismissViewControllerAnimated(true, completion: nil)
//remove current controller
dismissViewControllerAnimated(true, completion: nil)
if let topController = UIApplication.sharedApplication().keyWindow?.rootViewController {
if let navcontroller = topController.childViewControllers[0] as? UINavigationController{
navcontroller.popToRootViewControllerAnimated(false)
if let funnelcontroller = navcontroller.childViewControllers[0] as? FunnelController {
funnelcontroller.removeFromParentViewController();
funnelcontroller.view.removeFromSuperview();
let revealController = self.storyboard?.instantiateViewControllerWithIdentifier("DashboardController") as! SWRevealViewController
navcontroller.addChildViewController(revealController)
navcontroller.view.addSubview(revealController.view)
}
}
}
}
I believe you can do this by simply assigning a new array (with just the dashboard view, in your case) to the UINavigationController's viewControllers property.
Why do you want to use the same navigation controller instead of making a new one? Generally, instead of trying to change the root of a navigation controller, I would recommend just creating a new navigation controller.