In my viewDidLoad, I have the below code to hide the back button. However, when implemented, this disables the back button of further View Controllers in the chain of which I segue to. I'm not sure, but this may be to do with how I structure my app (please see image - note that the Navigation Controller on the far left is connected to a Tab Bar Controller).
// Removes back button
self.tabBarController?.navigationItem.hidesBackButton = true
self.tabBarController?.navigationItem.setHidesBackButton(true, animated: false)
self.tabBarController?.navigationItem.leftBarButtonItem = nil
I've also tried the following code, but this didn't work as well.
self.navigationItem.leftBarButtonItem = nil
self.navigationController?.navigationItem.leftBarButtonItem = nil
navigationItem.setLeftBarButton(nil, animated: false)
self.navigationItem.setLeftBarButton(nil, animated: false)
self.tabBarController?.navigationItem.leftBarButtonItem = nil
self.tabBarController?.navigationItem.setLeftBarButton(nil, animated: false)
self.navigationController?.navigationBar.topItem?.leftBarButtonItem = nil
If you only want to hide the back button on the current screen you should only clear the leftBarButtonItem. If you hide the backBarButtonItem too that will be applied to the next screen's navigationItem. Does this help?
try
self.parent?.navigationItem.setHidesBackButton(true, animated: false)
sometimes the viewController does not recognize it's navigation Controller without self.parent
Related
When I open a calendar event in my app using EKEventViewController using the code below it correctly displays my event in a modal view.
let eventModalVC = EKEventViewController()
eventModalVC.event = myEvent
eventModalVC.allowsEditing = true
present(eventModalVC, animated: true, completion: nil)
In portrait mode (using iOS 15) I can dismiss the modal using a swipe-down gesture. However, when I change to landscape orientation, the gesture does not work, and there is no back or cancel button either (like there is for the EKEventEditViewController). I could not find any property of the view controller that would enable me to dismiss it.
So the user is either stuck or has to turn the device into portrait mode. How can I fix this?
I was hoping that the EKEventViewController offers a similar convenient and intuitive way to dismiss it in landscape view as it does in portrait view but have not had any luck.
To get the back button I now enclosed my modal view in its own navigation controller. That reveals a "Done" button (as well as a delete button). Neither button dismisses the view. That can be done by implementing EKEventViewDelegate in the parent view controller.
let eventModalVC = EKEventViewController()
eventModalVC.event = myEvent
eventModalVC.allowsEditing = true
let nc = UINavigationController(rootViewController: eventModalVC)
eventModalVC.delegate = self
present(nc, animated: true, completion: nil)
...
// EKEventViewDelegate
func eventViewController(_ controller: EKEventViewController, didCompleteWith action: EKEventViewAction) {
if action == .done {
controller.dismiss(animated: true)
}
// handle deletion as well if needed
}
When i open CNContactViewController, It opens view without cancel and done button.
This issue only occurs in iOS13 and later.
How can i change the bar button colors?
I tried this link, but it is not working
Change color of cancel and done button in CNContactPicker
let controller = CNContactViewController(forNewContact: nil)
controller.delegate = self
navigationController?.pushViewController(controller, animated: true)
I have checked linked is working fine
change code to
navigationController?.pushViewController(controller, animated: true)
with this
self.present(UINavigationController(rootViewController: controller), animated:true)
I have two viewcontrollers. The first viewcontroller is collection view controller and i set self.navigationController?.hidesBarsOnSwipe = true in viewDidLoad().
When I push the second viewController from the visible cell of collectionView, the navigation bar is showing in the second viewController but if I scroll the collectionView cell and when push the navigation is not showing.
Can anyone tell me what the problem is?
scrolling is done via swipe gesture, so it triggers your code:
self.navigationController?.hidesBarsOnSwipe = true
because navigation controller is shared between all view controllers presented on top of it, it's properties (like hidden bar) preserves pushing / popping.
Common pattern is to change it's state in overrided lifecycle methods, eg:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self.navigationController?.hidesBarsOnSwipe = false
self.navigationController?.setNavigationBarHidden(false, animated: true)
}
and reverting those state in viewWillDisappear
When this property is set to true, an upward swipe hides the navigation bar and toolbar. A downward swipe shows both bars again. If the toolbar does not have any items, it remains visible even after a swipe. The default value of this property is false. (get it from apple)
See the doc https://developer.apple.com/documentation/uikit/uinavigationcontroller/1621883-hidesbarsonswipe
It means when you swipe up it will hide and when swipe down it will shown. That's the reason.
To fix it you can add following code to the other controller
[self.navigationController setNavigationBarHidden:NO animated:YES];
Don't get much insight what exactly you implemented, but try to unhide navigation bar in second view controller.
Add below code in viewDidLoad method of second View controller.
self.navigationController?.isNavigationBarHidden = false
Put this self.navigationController?.hidesBarsOnSwipe = false and this self.navigationController?.setNavigationBarHidden(false, animated: true) in your second view controller.
You might want to move your self.navigationController?.hidesBarsOnSwipe = true from viewDidLoad to viewWillAppear in your first view controller.
I have a View Controller which is the 2nd View Controller and need a navigation bar. The 1st one is a controller which doesn't need a Nav Bar and 3rd View Controller need a navigation bar.
As per stacks 3rd view controller will be no top of stack.
I have implemented these methods in 2nd View Controller:
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
if self.navigationController?.navigationBarHidden == true{
self.navigationController?.navigationBarHidden = false
}
self.navigationItem.backBarButtonItem = UIBarButtonItem(title: "", style: .Plain, target: nil, action: nil)
self.navigationController?.navigationBar.tintColor = Quikr_Util.colorWithHexString("#0083cb")
}
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
if self.navigationController?.navigationBarHidden == false{
self.navigationController?.navigationBarHidden = true
}
}
The things were working fine if a use a back bar button to go back from 3rd to 2nd View Controller.
Things got messy when I started to slide from one View Controller to another for example, when I slide half and then release.
It means sliding from 3rd to 2nd but release in between so it goes to 3rd View Controller rather than second .
What may be the best way to hide and unhide view navigation bars .
Secondly, how do sliding works , which functions will get called when sliding happens?
For your first question
To hide and show the Navigation Controller, in 2nd and 3rd View Controllers, You can use:
Hide:
navigationController?.setNavigationBarHidden(true, animated: false)
Show:
navigationController?.setNavigationBarHidden(false, animated: false)
There is not really a need to check if it is hidden or not.
For the second question, you can use UIGestureRecognizer
Edit:
Just to be clear, instead of hiding and showing the in the same file, hide and show in viewDidAppear() in needed swift files
I have read about similar problems where the problem was caused by having multiple navigation controllers, but I only have one. This is my navigation flow.
VC = UIViewController, NC = UINavigationController
VC1 -modal-> NC -root-> VC2 -show-> VC3
VC1 is not embedded in a navigation controller, I'm starting that modal segue using performSegueWithIdentifier:sender:.
VC2 then is using a show segue to present VC3, which is the one where the back button is not visible. It still works though. But, it does appear if I exit to the home screen and then enters the app again, as shown here:
https://gfycat.com/VelvetyThisHamster.
Any ideas why this is happening?
edit: To make things clear: I want the button both visible and functioning (it's not that it's working that's the problem, but that it's hidden)
EDIT 2:
If I change my navigation flow to this
NC -root-> VC2 -show-> VC3
then the back button works as intended. So the question is, how can I add a regular view controller without a navigation controller before the first navigation controller? I want it before because VC1 should not have a navigation bar and VC2 should be presented modally.
try this
Hidden
override func viewWillAppear(animated: Bool)
{
super.viewWillAppear(animated)
//use this
self.navigationItem.setHidesBackButton(true, animated: false)
//else use this
self.navigationItem.leftBarButtonItem = nil
}
Show
override func viewWillAppear(animated: Bool)
{
super.viewWillAppear(animated)
//use this
self.navigationItem.setHidesBackButton(false, animated: false)
//else
self.navigationController.navigationItem.backBarButtonItem.enabled = TRUE
}
Update
override func viewWillAppear(animated: Bool)
{
super.viewWillAppear(animated)
//use this
self.navigationItem.setHidesBackButton(false, animated: false)
//else
let backButton = UIBarButtonItem(title: "leftbutton", style: UIBarButtonItemStyle.Plain, target: self, action: "buttonMethod")
self.navigationItem.leftBarButtonItem = backButton
}
func buttonMethod() {
print("Perform action")
}
I think I found the source of the problem, so I'll post it here in case someone else runs into the same problem.
The modal presentation between VC1 and NC was made from a background queue (by calling performSegueWithIdentifier:sender: in the completion handler of an NSURLSessionDataTask to be precise). By dispatching that line of code to the main queue the problem seems to disappear.
Turn out, I had NavigationBar tint color set to "Clear". Once I changed it, the back button appeared.