Hierarchy of my Storyboard is:
-- Nav Controller -> First Controller
/-- Nav Controller2 -> Second Controller
/--- Nav Controller3 -> Third Controller
/---- Nav Controller4 -> Fourth Controller
HomeScreen ---> TabBarController ----- Nav Controller5 -> Fifth Controller
\---- Nav Controller6 -> Sixth Controller
The problem is: Navigation to Nav Controller6 is located on More table view. Nav Controller 6 has its own custom class extend from NavigationController. It has some methods like "viewDidLoad", "viewWillAppear" and so on. But it doesn't call from more table view.
The view redirects correctly, and navigation works fine but methods are not get called.
What should I look for? What I'm doing wrong?
Related
I'm trying to move from a View Controller to another.
I worte this function to use when the user tap on a button to move to the new view controller:
#objc private func infoButtonTap(){
let navVC = UINavigationController()
navVC.addChild(AboutViewController())
self.navigationController?.pushViewController(AboutViewController(), animated: true)
}
The problem is that the new view controller is presented on the screen but I don't have a navigation bar and a back button to move back.
I do not use Storyboard as I want to learn coding the UI.
I tried few things I found here on Stackoverflow but none worked for me.
How can I set the new view controller to have a navigation bar with back button?
UINavigationController has a variable isNavigationBarHidden
#objc private func infoButtonTap(){
let navVC = UINavigationController()
navVC.addChild(AboutViewController())
self.navigationController?.isNavigationBarHidden = false
self.navigationController?.pushViewController(AboutViewController(), animated: true)
}
You need to push the view Controller. Try this
let aboutVC = AboutVC()
self.navigationController?.pushViewController(aboutVC, animated: true)
You don't need to write any code.
Select the Root Navigation Controller the will control the app. In the Inspector Bar, select Simulated Metrics ( The Third Selection from the Right in the Inspector) and Check the Box " Is Initial View Controller". Then connect the next View controller which will be in essence the Landing page for the app. Once you connect other View Controllers to that View controller via a button for instance ( Select the button, then press Control Key + Drag to View Controller, select Show) , you will see the navigation Bar with "Back" displayed. Once that's done, you can add other view controllers and connect them from the landing page view controller and the Navigation Bars will be displayed.
For navigation to be visible and of use in an app , first you need to set up a Navigation controller with a Root view controller i.e your first controller and from there you can use push method on your navigation controller object to push a controller on to the stack.
For eg
let navVC = UINavigationController.init(rootViewController: YourFirstViewControllerObject())
navVC.pushViewController(NewViewControllerObj(), animated: true)
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.
I have a problem, I want to open two view Controllers on single tab from to different way.
Like:
Login Screen --> Home Screen --> On home screen two button A & B
1 When click on the button A, open A controller on tab controller tab1
2 When click on the button B, open B controller on tab controller tab1
I have 5 tab in tab controller.
Please help me for that issue.
Please refer attached screen for more help.
Thanks,
you can replace ViewController By using this
func tabBarController(tabBarController: UITabBarController, didSelectViewController viewController: UIViewController) -> Bool {
let selectIndex : NSInteger = (tabBarController.viewControllers?.index(of: viewController))!
if (selectIndex == 1) {
let vc = UIViewController() // your new Controller
var allviews = tabBarController.viewControllers
allviews?.remove(at: selectIndex)
allviews?.insert(vc, at: selectIndex)
tabBarController.setViewControllers(allviews, animated: true)
return false;
}
return true;
}
(Please add some more information to your question, or at least code to know what have you tried.)
By your question, It seems you need a Tab Bar Controller.
You use tab bar controller to organize your app into one or more distinct modes of operation. The view hierarchy of a tab bar controller is self contained. It is composed of views that the tab bar controller manages directly and views that are managed by content view controllers you provide. Each content view controller manages a distinct view hierarchy, and the tab bar controller coordinates the navigation between the view hierarchies.
I'm hitting my head against the wall with a navBar issue. See this sample project for a better idea of what I'm trying to achieve. Basically, my app structure is like this:
NavController -root-> ViewControllerA -> button -> push -> ViewControllerB --> ViewControllerC
| |
button -> presentModally |
| |
V |
PopoverViewController |
| |
button -> push to the nav controller |
| |
| |
---------------------------------------
A button on the second view controller (call it B) of the nav stack will present a modal view controller with a clear background (its modal presentation style is overCurrentContext to look like a popover):
Then, a button on the popover will push a new view controller on to the nav stack (call it C):
[
The popover is presented by B as opposed to the actual nav controller (B defines the presentation context). This so that when the popover pushes C on the stack, C doesn't just cover B, but covers the popover as well.
The problem arises when dismissing C. The nav stack pops back to B with the popover still on top (which is my intention). However, B now fills the entire frame of the nav view controller (before C was pushed, B's top was pinned to the navBar). This causes views near the top of B to be clipped by the navBar:
A look at the UI Inspector confirms that this is because B's view now fills the nav controller's view:
This was not the case before C was presented. Any ideas as to what's causing this to happen?
You are manually pushing a view controller onto the stack which doesn't have a navigation controller. A better way to do it would be to segue from view controller B to view controller C using a segue identifier. Once you setup the segue in the storyboard you will see that view controller C gets a nav bar automatically. You might want to use a delegate method from the popover view controller to B to trigger the segue.
I had a problem very similar to this one. I was presenting a view controller using a .overCurrentContext presentation mode. When the viewController was displayed the navigation was over it!
To solve the problem I just asked to the navigation show the new view controller instead of the old viewController.
viewController.navigationController?.present(navigationController, animated: true, completion: nil)
Doing by this way the viewController will not be behind the navigation anymore. I hope it helps someone.
swift 5
I did this way:
let vc = viewControllerToDisplay()
let navVc = UINavigationController(rootViewController: vc)
navVc.modalPresentationStyle = .overCurrentContext
navVc.modalTransitionStyle = .crossDissolve
navigationController?.present(navVc, animated: true, completion: nil)
I have the following setup
-> Navigation Controller -> View Controller A -> View Controller B
B has some left and right navigation items which show up in this sequence
I have another flow where
-> Navigation Controller -> View Controller A -> View Controller C -> View Controller B
In ViewController C, when a save button is sliced, I manually trigger the segue to show View B. But, in this scenario, the navigation bar does not show up.
If I embed controller B in a navigation controller, then in the prepareFor Segue of Controller C, I cannot refer this as the destination. How do I fix this?
I am putting in some screen shots of the settings below:
This is the nav bar in A
The segue from A->B. This is triggered by selecting a row in a table View
This is how the nav bar in B looks when triggered from A
The segue from A->C
This is the nav bar in C
The segue from C->B
From C to B, I am triggering the segue as below:
dispatch_async(dispatch_get_main_queue(), {
self.performSegueWithIdentifier("SegueGroupView", sender: self)
})
On this trigger, the nav bar in B is not appearing