On my mainVC I have a TableView with a button that should open the secondVC, where I can add things to show then in the Table, with the kind: "Present As Popover".
I'm opening the secondVC with performSegue(withIdentifier:"goToOtherView", sender: nil.
class FirstViewController: UIViewController {
#IBOutlet weak var tableView: UITableView!
var groupData = ["Data, Data1, Data2"]
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .green
tableView.delegate = self
tableView.dataSource = self
}
#IBAction func btnTapped(_ sender: Any) {
performSegue(withIdentifier: "goToOtherView", sender: nil)
}
override func viewWillAppear(_ animated: Bool) {
print("FirstViewController will appear")
}
override func viewDidAppear(_ animated: Bool) {
print("FirstViewController did appear")
}
override func viewWillDisappear(_ animated: Bool) {
print("FirstViewController will disappear")
}
override func viewDidDisappear(_ animated: Bool) {
print("FirstViewController did disappear")
}
}
class SecondViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .blue
}
override func viewWillAppear(_ animated: Bool) {
print("SecoundViewController will appear")
}
override func viewDidAppear(_ animated: Bool) {
print("SecoundViewController did appear")
}
override func viewWillDisappear(_ animated: Bool) {
print("SecoundViewController will disappear")
}
override func viewDidDisappear(_ animated: Bool) {
print("SecoundViewController did disappear")
}
}
Storyboard
When I start the App
When I open the secondVC
And when I close the secondVC
The FirstViewController willDisappear and didDisappear are never being called, or even when the secondVC is closed the willAppear and didAppear. I want to call the function tableView.reloadData() when the FirstView willAppear/didAppear
It's kinda the same like the IOS default clock app, when you add a new alarm clock.
Quick guess, but I think that’s because of the presentation mode being pageSheet
Can you try to change it to fullScreen?
You can also change your segue configuration to be like:
View disappear won't be called since the view does not completely disappears from the window
Related
The large title of navigation item comes out when the app just describes execution. However, when I move to another page and come back, that mode is turned off. Create a viewDidLoad for each page as follows: What's the problem?
class CollectionViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
navigationController?.navigationBar.prefersLargeTitles = true
self.navigationItem.largeTitleDisplayMode = .always
}
next page
class AssetCollectionViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
self.navigationItem.largeTitleDisplayMode = .never
}
Possibly adding code didn't work.
override func viewDidDisappear(_ animated: Bool) {
self.navigationItem.largeTitleDisplayMode = .always
}
Change titleDisplay mode in viewWillppear function as it will always execute
class CollectionViewController: UIViewController {
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
navigationController?.navigationBar.prefersLargeTitles = true
self.navigationItem.largeTitleDisplayMode = .always
}
How about doing all the implementation in your CollectionViewController like so:
override func viewWillDisappear(_ animated: Bool) {
navigationController?.navigationBar.prefersLargeTitles = false
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
navigationController?.navigationBar.prefersLargeTitles = true
}
When you're setting navigationItem.largeTitleDisplayMode in viewDidDisappear(_:), you're doing it for the current controller's navigationItem.
I suggest you to create UINavigationController subclass with:
override func viewDidLoad() {
super.viewDidLoad()
navigationBar.prefersLargeTitles = true
}
Then set navigationItem.largeTitleDisplayMode to .never in controllers, where you don't want large title.
I have a View Controller with a button..
This button calls a "Present as Popover Seague" to a second view controller.
The second view controller has a close button with this function:
#IBAction func exit(_ sender: UIButton) {
self.dismiss(animated: true, completion: nil)
}
Now I would like to do something in the first controller, after the second Controller is dismissed.
In the first view controller I tried this functions:
override func viewDidAppear(_ animated: Bool) {
print("viewDidAppear")
}
override func viewWillAppear(_ animated: Bool) {
print("viewWillAppear")
}
but no console log will shown.
Where is my mistake?
FirstViewContorller
import UIKit
class firstVC: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
//ERROR
secondVC.dismissCompletion = {
print("dismissCompletion")
}
}
}
SecondVC (popover)
import UIKit
class secondVC: UIViewController {
var dismissCompletion: (() -> Void)?
// EXIT POPOVER
#IBAction func exit(_ sender: UIButton) {
self.dismiss(animated: true, completion: dismissCompletion)
}
}
The viewDidAppear() method of the main view controller won't be called because of the popover presentation style you use. If you choose to present the second view controller full screen - those methods will fire.
If we're sticking with the popover, the first thing you need to do is in your second view controller, the one that's being presented, add a property for a closure that will be executed upon its dismiss:
class PopoverViewController: UIViewContoller {
var dismissCompletion: (() -> Void)?
#IBAction func exit(_ sender: UIButton) {
self.dismiss(animated: true, completion: dismissCompletion)
}
}
And in your main view controller you define what needs to be done upon the popover's dismiss:
popoverViewContoller.dismissCompletion = {
// do stuff
}
UPDATE:
I assume you've setup the segue in your storyboard. I also assume that in your storyboard you've given the view controllers their respective class names:
This is what your code should look like:
class FirstViewController: UIViewController {
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
guard let secondVC = segue.destination as? SecondViewController else {
return
}
secondVC.dismissCompletion = {
print("Popover dismissed")
}
}
}
class SecondViewController: UIViewController {
var dismissCompletion: (() -> Void)?
#IBAction func exit(_ sender: Any) {
dismiss(animated: true, completion: dismissCompletion)
}
}
Please note the classes naming and the way I got the secondVC instance.
I'm trying to understand the life cycle of view controllers. I need to use TabBar to switch controllers. And when switching controllers, I need the label to display life-cycle methods, not only of the controller on which I now find, but also from others.
I created an empty array private var arrayOfMethods = [String]() in which I add a triggered method every time.
class ViewController: UIViewController {
private var arrayOfMethods = [String]()
#IBOutlet var greenLabel: UILabel!
#IBOutlet var blueLabel: UILabel!
#IBOutlet var yellowLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
printMessage()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
printMessage()
}
override func viewDidAppear(_ animated: Bool) {
super.viewWillAppear(animated)
printMessage()
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
printMessage()
}
override func viewDidDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
printMessage()
}
func printMessage(line: Int = #line, function: String = #function) {
print("\(title ?? "nil"). Line: \(line) of function \(function)")
arrayOfMethods.append(function)
let string = arrayOfMethods.joined(separator: "\n")
greenLabel.text = "\(title ?? "nil") \(string)"
}
}
You can create a common class and call its function from all of your view controllers
class Helper: NSObject {
private var arrayOfMethods = [String]()
static let shared = Helper()
let mainLabel = UITextView(frame: CGRect(x: 100, y: 100, width: 300, height: 300))
private override init() {
super.init()
}
func printMessage(vc: UIViewController, line: Int = #line, function: String = #function) {
print("\(vc.title ?? "nil"). Line: \(line) of function \(function)")
arrayOfMethods.append( (vc.title ?? "nil") + "-" + function)
let string = arrayOfMethods.joined(separator: "\n")
guard let window = UIApplication.shared.keyWindow else { return }
if !window.subviews.contains(mainLabel) {
window.addSubview(mainLabel)
window.bringSubviewToFront(mainLabel)
}
mainLabel.text = string
}
}
And call this singleton class method from all your view controllers like this
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
Helper.shared.printMessage(vc: self)
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
Helper.shared.printMessage(vc: self)
}
override func viewDidAppear(_ animated: Bool) {
super.viewWillAppear(animated)
Helper.shared.printMessage(vc: self)
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
Helper.shared.printMessage(vc: self)
}
override func viewDidDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
Helper.shared.printMessage(vc: self)
}
}
Output
Say, I have a label show : Loading...
problem: When return from VC(2). The label is not hidden.
How to hide it when return from VC(2) and dont hide it when in navigating to VC(2) and show the message : Loading....
in VC(1)
#IBOutlet weak var lbLoadingMsg
In viewDidLoad() {
lbLoadingMsg.hidden = true
}
-2-- turn it on when prepare to navigate to VC(2)
override func shouldPerformSegueWithIdentifier(identifier: String?, sender: AnyObject?) -> Bool
{
--code--
lbLoadingMsg.hidden = false
}
Override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!){
}
You can use NSNotificationCenter for that.
Follow this simple steps:
1.In your VC(2) add this code into your button from where you are going back:
#IBAction func goBack(sender: AnyObject) {
NSNotificationCenter.defaultCenter().postNotificationName("hide", object: nil)
self.dismissViewControllerAnimated(true, completion: nil)
}
2.In your First View add this code into viewDidLoad method:
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: "hideLabel:", name:"hide", object: nil)
}
now this method will call this function:
func hideLabel(notification: NSNotification){
self.lbLoadingMsg.hidden = true
}
And this will hide your label in first view when ever goBack button will pressed from first view.
Hope this will help you.
Write this in VC2
,
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
var identifier = segue.identifier
if(identifier! == "yourIdentifier"){
var vc1:VC1 = segue.destinationViewController as! VC1
vc1.lbLoadingMsg.hidden = true
}
}
func viewDidAppear(_ animated: Bool) {
lbLoadingMsg.hidden = true
}
Move
lbLoadingMsg.hidden = true
line from viewDidLoad to viewDidAppear. I think most quicker way.
Where and how do I have to reset hidesBarsOnSwipe? I set the option in a View Controller which I push and want to reset it for the View Controller which did the push. What I tried until now is setting hidesBarsOnSwipe to false in the viewDidDisappear and in the viewDidLoad of the pushing ViewController.
The Navigationbar is still disappearing.
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
if (!visiblePOIs.isEmpty) {
let beaconInfo = visiblePOIs[indexPath.item]
var controller = storyboard!.instantiateViewControllerWithIdentifier("DetailController")! as! DetailController
controller.setup(beaconInfo)
self.parentViewController!.navigationController?.pushViewController(controller, animated: true)
}
}
DetailController
override func viewDidLoad() {
super.viewDidLoad()
webView.delegate = self
navigationController?.hidesBarsOnSwipe = true
self.automaticallyAdjustsScrollViewInsets = false
}
next view controller write in viewDidload
First Vc
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
self.navigationController?.hidesBarsOnSwipe = true
}
Second VC
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
self.navigationController?.hidesBarsOnSwipe = false
self.navigationController?.setNavigationBarHidden(false, animated: true)
}
I hope its works
I had your exact problem. Here's how I solved it. (You can adapt this based on your needs.)
class MyViewController: UITableViewController {
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
//Correct the nav bar state unwinding from segues
self.navigationController?.hidesBarsOnSwipe = true
}
override func willMoveToParentViewController(parent: UIViewController?) {
super.willMoveToParentViewController(parent)
//Toggle the auto-hiding nav bar when this view gets added/removed from the nav controller
self.navigationController?.hidesBarsOnSwipe = !self.navigationController!.hidesBarsOnSwipe
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
super.prepareForSegue(segue, sender: sender)
//Reset the nav bar to visible when segueing to another view
self.navigationController?.navigationBarHidden = false
self.navigationController?.hidesBarsOnSwipe = false
}
}
This approach allows you to limit the functionality of the auto-hiding feature to the desired view controller without adding code to all associated view controllers.