Can I use dismiss for screen movement using NavigationController? - ios

I'm using NavigationController to operate the view.
If the value is exceeded on the first view and the value is not satisfied with the 'if' on the second view, I hope 'dismiss' will work.
I have made a similar simple example.
//First View
class ViewController: UIViewController {
#IBAction func goSecond(_ sender: Any) {
let Storyboard = UIStoryboard(name: "Main", bundle: nil)
let DvC = Storyboard.instantiateViewController(withIdentifier: "SecondViewController") as! SecondViewController
self.navigationController?.pushViewController(DvC, animated: true)
}
override func viewDidLoad() {
super.viewDidLoad()
}
}
//Second View
class SecondViewController: UIViewController {
#IBAction func goThird(_ sender: Any) {
let Storyboard = UIStoryboard(name: "Main", bundle: nil)
let DvC = Storyboard.instantiateViewController(withIdentifier: "ThirdViewController") as! ThirdViewController
let num = 1
DvC.num = num
self.navigationController?.pushViewController(DvC, animated: true)
}
override func viewDidLoad() {
super.viewDidLoad()
}
}
//Third View
class ThirdViewController: UIViewController {
var num = Int()
override func viewDidLoad() {
super.viewDidLoad()
print("num: ")
print(num)
if(num != 2) {
print("Success")
// dismiss(animated: true, completion: nil)
// navigationController?.dismiss(animated: true, completion: nil)
} else {
print("Failed")
}
}
}
The third view shows "Success", but the codes below it do not work.
dismiss(animated: true, completion: nil) // not work
navigationController?.dismiss(animated: true, completion: nil) // not work
Pressing the button on the first view moves to the second view, and pressing the button on the second view moves to the third view.
If the value passed when I go to the third view is not satisfied with 'if', I want to go back to the first view.
I want the second and third views to end, not just the screen shift.
Like the finish() of Android.
How can I exit the second and third views and return to the first view?

You are pushing the view controllers onto the stack. dismiss is for dismissing VCs presented modally.
What you want to do is pop the VC to go back one.
navigationController?.popViewController(animated: true)
or to go back to the root view.
navigationController?.popToRootViewController(animated: true)

Related

How to reload present view controller swift?

I have two Present view controllers. The thing i want to do is when the second Present view controller is dismissed it will automatically reload the first present view controller(Table view). note: first view controller holds a table view, basically i want to reload the table view of first controller.
ViewWillAppear code:
override func viewWillAppear(_ animated: Bool) {
tableViewReloadFromCreateProductVC()
}
func tableViewReloadFromCreateProductVC () {
tableView.reloadData()
}
Calling from second view controller code:
SecondViewController.tableViewReloadFromCreateProductVC()
navigationController?.popViewController(animated: true)
dismiss(animated: true, completion: nil)
FirstViewController calling 2nd view controller
#IBAction func CallSecondViewButton(_ sender: Any) {
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let controller = storyboard.instantiateViewController(withIdentifier: "YourViewControllerIdentifier") as! YourViewController
controller.modalPresentationStyle = .fullScreen
self.present(controller, animated: true, completion: nil)
}
just write the code in viewWillAppear() method of the view controller that you want to reload like this
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(true)
//perform api call if any
yourTableView.reloadData()
}
2nd view controller
#IBAction func CloseButton(_ sender: Any) {
self.dismiss(animated: true, completion: nil)
}
after dissmissing the viewWillAppear method of firstViewController will autometically called.
The First two snippets are for first view controller and the last one is for second view controller
Reloading the entire table view could sometimes be costly and it also sounds like you're making an API call as well so unless you want your table view to be reloaded and the API call made every time the view controller becomes visible whether or not you've made changes to it, you want the reloading to be done only when it's necessary.
You can try it in a few different ways:
class CreateProductVC: UITableViewController {
#IBAction func presentSecondVC() {
if let secondVC = storyboard?.instantiateViewController(identifier: "SecondVC") as? SecondViewController {
secondVC.delegate = self
present(secondVC, animated: true, completion: nil)
}
}
}
class SecondViewController: UIViewController {
weak var delegate: CreateProductVC?
#IBAction func dismissSecondVC() {
self.dismiss(animated: true) {
self.delegate?.tableView.reloadData()
}
}
}
or
class CreateProductVC: UITableViewController {
#IBAction func presentSecondVC() {
if let secondVC = storyboard?.instantiateViewController(identifier: "SecondVC") as? SecondViewController {
secondVC.isDismissed = { [weak self] in
self?.tableView.reloadData()
}
present(secondVC, animated: true, completion: nil)
}
}
}
class SecondViewController: UIViewController {
var isDismissed: (() -> Void)?
#IBAction func dismissSecondVC() {
self.dismiss(animated: true) {
self.isDismissed?()
}
}
}
or if you want more fine-grained control over what to do with the new data:
protocol ReloadVC {
func reload(_ value: String)
}
class CreateProductVC: UITableViewController, ReloadVC {
var dataSource: [String]! {
didSet {
tableView.reloadData()
}
}
#IBAction func presentSecondVC() {
if let secondVC = storyboard?.instantiateViewController(identifier: "SecondVC") as? SecondViewController {
secondVC.delegate = self
present(secondVC, animated: true, completion: nil)
}
}
func reload(_ value: String) {
dataSource.append(value)
}
}
class SecondViewController: UIViewController {
var delegate: ReloadVC?
#IBAction func dismissSecondVC() {
self.dismiss(animated: true) {
let someValue = "Some Value"
self.delegate?.reload(someValue)
}
}
}

How to dismiss previous Viewcontroller after presenting new Viewcontroller using Swift?

My Scenario, In my project I am maintaining three ViewController (Main, VC1 and VC2). In main ViewController I am maintaining UIButton, This button click to VC1 presenting model view controller. Again, VC1 I am maintain UIButton with action click to present model to VC2. After VC2 presenting I need to dismiss VC1.
// presenting ViewController
var presentingViewController: UIViewController! = self.presentingViewController
self.dismissViewControllerAnimated(false) {
// go back to MainMenuView as the eyes of the user
presentingViewController.dismissViewControllerAnimated(false, completion: nil)
}
Try this in VC2's close button action
var vc = self.navigationController?.presentingViewController
while vc?.presentingViewController != nil {
vc = vc?.presentingViewController
}
vc?.dismiss(animated: true, completion: nil)
Hope this will work:
You need to have a UIViewController as a base, in this case MainViewController is the base ViewController. You need to use a protocol to call the navigation between Controllers.
you can do using protocol:-
In to your FirstViewController setting Protocol :
protocol FirstViewControllerProtocol {
func dismissViewController()
}
class FirstViewController: UIViewController {
var delegate:FirstViewControllerProtocol!
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
#IBAction func goBack(sender: AnyObject) {
self.dismissViewControllerAnimated(true) {
self.delegate!.dismissViewController()
}
}
Now in your MainViewController
class MainViewController: UIViewController, FirstViewControllerProtocol {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func goToFirstViewController(sender: AnyObject) {
let viewController = self.storyboard?.instantiateViewControllerWithIdentifier(String(FirstViewController)) as! FirstViewController
viewController.delegate = self
self.presentViewController(viewController, animated: true, completion: nil)
}
//MARK: Protocol for dismiss
func dismissViewController() {
if let viewController = self.storyboard?.instantiateViewControllerWithIdentifier(String(SecondViewController)){
self.presentViewController(viewController, animated: true, completion: nil)
}
}
To solve the problem statement, what you can do is present VC2 using Main instead of VC1.
We can get the reference to Main in VC1 using
self.presentingViewController
When VC2 is presented, dismiss VC1 in the completionHandler of present(_:animated:completion:) method
class Main: UIViewController {
#IBAction func onTapButton(_ sender: UIButton) {
let vc1 = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "VC1")
self.present(vc1, animated: true, completion: nil)
}
}
class VC1: UIViewController {
#IBAction func onTapButton(_ sender: UIButton) {
let vc2 = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "VC2")
vc2.view.backgroundColor = .blue
self.dismiss(animated: false, completion: nil)
self.presentingViewController?.present(vc2, animated: true, completion: nil)
}
}
class VC2: UIViewController {
}
This approach is giving the expected output. Let me in case anything else is required.
You need to open vc2 from the mainVC - In order to do this you need a delegate method which will tell mainVC to close the current opened vc (i.e. vc1) and in the success block open vc2.
Code Snipet:-
dismiss(animated: false) {
//Open vc2
present(vc2)
}
In this case you need to call dismiss from the view controller over which your other view controllers are presented(Main in your case).
As you stated your situation in the question above Main presents VC1 and VC1 then presents VC2:
then calling Main.dismiss(animated: true, completion: nil) will dismiss VC1 and VC2 simultaneously.
If you don't have a reference to the root controller(Main), you could chain a couple of presentingViewController properties to access it; Something like this in the topmost controller(VC2):
presentingViewController?.presentingViewController?.dismiss(animated: true)
I hope this helps.
There is a present(_:animated:completion:) method which takes a completion. Inside that you can dismiss your VC1.
Your code will look something like this
#IBAction func ButtonTapped(_ sender: Any) {
present(VC2, animated: true) {
dismiss(animated: true, completion: nil)
}
}

how to enable the customview controller with view after dismiss Second viewcontroller in swift

I have two view controller
imag
1.first view controller is main and second is CustomAlertviw controller
main view controller is like above image, when I click continues am showing the customalertview controller, like image. when click the enter pin button I have to dismiss view contoller and show the view controller with uiview on main view controller but tried, it's showing the view controller, there one more custom view is not showing it crashing my app
main view code
#IBAction func backButtonClicked(_ sender: UIButton) {
let myAlert = UIStoryboard(name: "CustomAlertview", bundle: nil).instantiateViewController(withIdentifier: "CustomAlertViewController") as? CustomAlertViewController
myAlert?.modalPresentationStyle = UIModalPresentationStyle.overCurrentContext
myAlert?.modalTransitionStyle = UIModalTransitionStyle.crossDissolve
self.present(myAlert!, animated: true, completion: nil)
}
Customalertview controller
#IBAction func enterPinButtonClick(_ sender: Any) {
self.dismiss(animated: true, completion: nil)
let myAlert = UIStoryboard(name: "ScanAndPay", bundle: nil).instantiateViewController(withIdentifier: "ScanAndPayDetailsEntryViewController") as? ScanAndPayDetailsEntryViewController
myAlert?.modalPresentationStyle = UIModalPresentationStyle.overCurrentContext
myAlert?.modalTransitionStyle = UIModalTransitionStyle.crossDissolve
self.present(myAlert!, animated: true, completion: nil)
myAlert.valuespass()
}
inside main view controller one function calling from the customalrerview
func valuespass()
{
DispatchQueue.main.async {
self.authType = 1
self.authStatus = false
print("this is calling")
self.pinStatusLabel.text = "Please enter a 4-digit Security PIN"
}
when I am calling this function from the custom alert view application is crashing and showing the hread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value this error. how to can show the all information after dismissing the custom view controller.
You are almost done. present ScanAndPay from FirstView instead of CustomAlertview.
I have done using Delegate as I think it will be fit in this scenario. Follow below steps -
Step 1:
In FirstViewController ,
Add - CustomAlertviewDelegate something like this -
class FirstViewController: UIViewController, CustomAlertviewDelegate {
Now replace your backButtonClicked method -
#IBAction func backButtonClicked(_ sender: UIButton) {
let myAlert = UIStoryboard(name: "CustomAlertview", bundle: nil).instantiateViewController(withIdentifier: "CustomAlertViewController") as? CustomAlertViewController
myAlert?.modalPresentationStyle = UIModalPresentationStyle.overCurrentContext
myAlert?.modalTransitionStyle = UIModalTransitionStyle.crossDissolve
myAlert.delegate = self
self.present(myAlert!, animated: true, completion: nil)
}
Add a new Delegate method of CustomAlertviewDelegate -
func ScanAndPayView(){
DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
let myAlert = UIStoryboard(name: "ScanAndPay", bundle: nil).instantiateViewController(withIdentifier: "ScanAndPayDetailsEntryViewController") as? ScanAndPayDetailsEntryViewController
myAlert?.modalPresentationStyle = UIModalPresentationStyle.overCurrentContext
myAlert?.modalTransitionStyle = UIModalTransitionStyle.crossDissolve
self.present(myAlert!, animated: true, completion: nil)
}
}
Step 2:
Now time for CustomAlertview ,
Add protocol for delegate top of the Class -
protocol CustomAlertviewDelegate: class {
func ScanAndPayView()
}
class CustomAlertview: UIViewController{
weak var delegate : CustomAlertviewDelegate!
...
override func viewDidLoad() { // Rest of your code
}
Now time to dismiss current view controller and notify FirstViewController for presenting ScanAndPay view Controller -
#IBAction func enterPinButtonClick(_ sender: Any) {
delegate.ScanAndPayView()
self.dismiss(animated: true, completion: nil)
}
Hope it will help you to achieve what you want.

How to dismiss the current ViewController and change to the new ViewController in Swift?

I am new to iOS swift. I have three ViewController.
The page-A is root controller and it will present to the page-B. It has a timer in page-B. After 5 sec, it will change View from page-B to page-C , and close the page-B at the same time.
In the ViewControll-B
class AViewController: UIViewController {
var timer: Timer?
override func viewDidLoad() {
super.viewDidLoad()
//set the timer , and chagne view to C ViewController
Timer.scheduledTimer(timeInterval: 5,
target: self,
selector: #selector(self.changeToAnswerView),
userInfo: nil,
repeats: false)
}
#objc func changeToAnswerView() {
dismissLoader()
}
func dismissLoader() {
dismiss(animated: true) {
print("Dismissing Loader view Controller")
}
}
override func viewWillDisappear(_ animated: Bool) {
//change view to Answer ViewController
let filterVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "CViewControllerID")
filterVC.modalPresentationStyle = UIModalPresentationStyle.custom
self.present(filterVC, animated: true, completion: nil)
}
}
After timer execute for 5 sec , the BViewController will dismiss itself and present to the BViewController.
But the following error will happened:
whose view is not in the window hierarchy
Did I missing something?
Question:
How to dismiss the current ViewController and change to the new ViewController in Swift?
Thanks in advance.
Here is the Working code that you can Try
Your Controller which is Dismissed and Tend to make a new controller being presented
import UIKit
class pdfVC: UIViewController
{
var timer : Timer?
override func viewDidLoad()
{
super.viewDidLoad()
timer = Timer.scheduledTimer(timeInterval: 3, target: self, selector: #selector(pdfVC.timerAction), userInfo: nil, repeats: false)
}
#objc func timerAction()
{
if timer != nil {
timer?.invalidate()
dismiss(animated: true, completion: {
print("Dismissed")
})
}
}
override func viewWillDisappear(_ animated: Bool) {
if self.isBeingDismissed {
let filterVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "demoViewController")
filterVC.modalPresentationStyle = UIModalPresentationStyle.custom
print("called")
self.presentingViewController?.present(filterVC, animated: true, completion: nil)
}
}
}
Output
Try changing dismissLoader function to something like:
func dismissLoader() {
dismiss(animated: true) {
print("Dismissing Loader view Controller")
if let presentingController = self.presentingViewController {
let filterVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "BViewControllerID")
filterVC.modalPresentationStyle = UIModalPresentationStyle.custom
presentingController.present(filterVC, animated: true, completion: nil)
}
}
}
and remove the viewWillDisappear function.
The problem is that you are trying to present the BViewController from the loader after being dismissed (i.e removed from window hierarchy) which at that point doesn't exist.
So, the solution is that you could get a reference to the presenting view controller which is presenting the loader and which will appear after dismissing the loader and present the new view controller from there.
in your B view controller after its dismissed,
in its completion handler
self.dismiss(animated: true) {
if let presentingVC = self.presentingViewController {
present c view controller here
}
}
this above is one way to do so, another way is, through delegate
in A view controller:
if let bVC = self.storyboard.instantiateViewController(withIdentifier: B.controllerIdentifier) as? B {
bVC.delegate = self
self.present(bVC, animated: true, completion: nil)
}
inside B View Controller
add delegate method for Protocol
protocol BProtocol: class {
func didClose()
}
and in B dismiss
var delegate: BProtocol?
self.dismiss(animated: true) {
self.delegate?.didClose()
}
this delegate will be implemented by A ViewController as
extension AViewController: BProtocol {
func didClose() {
//present C
}
}
You are trying use a reference (instance) of view controller, that would no longer exist in memory.
Try this
if let presentingVC = self.presentingViewController {
let filterVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "CViewControllerID")
filterVC.modalPresentationStyle = UIModalPresentationStyle.custom
presentingVC.present(filterVC, animated: true, completion: nil)
}
Note: Present a new view controller (filterVC) once your current view controller is dismissed. A view controller can present only a one view controller at time (if you choose present modally). Perform this operation after a delay of 1 second..
Edit
Try with this edited code.
Class AViewController: UIViewController {
var timer: Timer?
var presentingVC: UIViewController?
override func viewDidLoad() {
super.viewDidLoad()
//set the timer , and chagne view to C ViewController
Timer.scheduledTimer(timeInterval: 5,
target: self,
selector: #selector(self.changeToAnswerView),
userInfo: nil,
repeats: false)
}
#objc func changeToAnswerView() {
dismissLoader()
}
func dismissLoader() {
dismiss(animated: true) {
print("Dismissing Loader view Controller")
}
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
//change view to Answer ViewController
if let presentingVC = self.presentingViewController {
self.presentingVC = presentingVC
}
}
override func viewWillDisappear(_ animated: Bool) {
//change view to Answer ViewController
super.viewWillDisappear(animated)
if let presentingVC = self.presentingVC {
let filterVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "CViewControllerID")
filterVC.modalPresentationStyle = UIModalPresentationStyle.custom
presentingVC?.present(filterVC, animated: true, completion: nil)
} else {
print("Presenting View controller is nil")
}
}
}

How to dismiss the current ViewController and go to another View in Swift

I am new to Swift and I want to know how to dismiss the current view controller and go to another view.
My storyboard is like the following: MainMenuView -> GameViewController -> GameOverView. I want to dismiss the GameViewController to go to the GameOverView, not to the MainMenuView.
I use the following code in my MainMenuView:
#IBAction func StartButton(sender: UIButton) {
let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
let nextViewController = storyBoard.instantiateViewControllerWithIdentifier("GameViewController") as! GameViewController
self.presentViewController(nextViewController, animated:true, completion:nil)
restGame()
}
In the GameViewController, I use this code, but it doesn't dismiss the GameViewController.
let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
let nextViewController = storyBoard.instantiateViewControllerWithIdentifier("GameOverView") as! GameOverView
self.presentViewController(nextViewController, animated:true, completion:nil)
This is My GameOverView Code :
class GameOverView: UIViewController{
// save the presenting ViewController
var presentingViewController :UIViewController! = self.presentViewController
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func ReplayButton(sender: UIButton) {
restGame()
didPressClose()
}
#IBAction func ReturnMainMenu(sender: UIButton) {
Data.GameStarted = 1
self.dismissViewControllerAnimated(false) {
// go back to MainMenuView as the eyes of the user
self.presentingViewController.dismissViewControllerAnimated(false, completion: nil);
}
/* let storyBoard : UIStoryboard = UIStoryboard(name: "Main", bundle:nil)
let nextViewController = storyBoard.instantiateViewControllerWithIdentifier("MainScene") as! MainScene
self.presentViewController(nextViewController, animated:true, completion:nil)*/
}
func restGame(){
Data.score = 0
Data.GameHolder = 3
Data.GameStarted = 1
Data.PlayerLife = 3.0
Data.BonusHolder = 30
Data.BonusTimer = 0
}
func didPressClose()
{
self.self.dismissViewControllerAnimated(true, completion:nil)
}
override func shouldAutorotate() -> Bool {
return false
}
deinit{
print("GameOverView is being deInitialized.");
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Release any cached data, images, etc that aren't in use.
}
override func prefersStatusBarHidden() -> Bool {
return true
}
}
Any suggestions?
What you can do is let the GameOverView be presented, after all when you presenting it the GameViewController is below in the hierarchy, and then in your GameOverView run the following code to close both when you want to dismiss the GameOverView, like in the following way:
#IBAction func ReturnMainMenu(sender: UIButton) {
// save the presenting ViewController
var presentingViewController: UIViewController! = self.presentingViewController
self.dismissViewControllerAnimated(false) {
// go back to MainMenuView as the eyes of the user
presentingViewController.dismissViewControllerAnimated(false, completion: nil)
}
}
The above code need to be called when you want to dismiss the GameOverView.
I hope this help you.
The below code will take you to the main VC, Here's a tried and tested piece of code.
self.view.window!.rootViewController?.dismiss(animated: false, completion: nil)

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