So I have a view controller which I display as follows:
func showProfileForTrainer(trainer: Trainers) {
let viewPTProfileVC = ViewPTProfileVC()
viewPTProfileVC.trainer = trainer
self.navigationController?.pushViewController(viewPTProfileVC, animated: true)
}
But when trying to dismiss the view, I cannot get it to work. It has a back button in a navigation bar which functions fine, but when trying to dismiss the view via a button for example, it does nothing. I have currently tried:
func handleMessageTrainer() {
dismiss(animated: true) {
print(1)
self.tabBarVC?.showChatLogForTrainer(trainer: self.trainer!)
}
self.dismiss(animated: true) {
print(2)
self.tabBarVC?.showChatLogForTrainer(trainer: self.trainer!)
}
navigationController?.dismiss(animated: true, completion: {
print(3)
self.tabBarVC?.showChatLogForTrainer(trainer: self.trainer!)
})
self.navigationController?.dismiss(animated: true, completion: {
print(4)
self.tabBarVC?.showChatLogForTrainer(trainer: self.trainer!)
})
print(5)
}
As you can see I have tried varying ways and none work, and the console just outputs 5.
Frustratingly, elsewhere in my app I presented a view in the same way as shown at the beginning and it dismissed fine using dismiss(animated: true) { ... }
Any idea why it won't work here?
You must pop the view controller from the corresponding navigation controller:
self.navigationController?.popViewController(animated: true)
If you are using pushviewcontroller method then to dismiss you have to use popviewcontroller method.
Try this:
self.navigationController?.popViewController(animated: true)
Related
When I dismiss a view it refuses to trigger the completion function and I don't know why.
Here I expect the print statement to execute but it never does.
#IBAction func tapBack(_ sender: Any) {
self.navigationController?.popViewController(animated: true)
self.dismiss(animated: true, completion: {
print("this should print")
})
}
Source Code
https://github.com/omenking/DismissCompletion
I also tried wrapping it in DispatchQueue.main.async but I had no luck.
Would you not be better off calling the function on the tap? Example:
func dismissController() {
self.navigationController?.popViewController(animated: true)
self.dismiss(animated: true, completion: nil)
}
And then on your button:
#IBAction func tapBack(_ sender: Any) {
dismissController()
print("this should print")
}
I've just downloaded your project and tried this and it prints.
First of all , I am assuming that since you are popping the view controller, you must have pushed it into the navigation Stack.
Secondly, if you did do it , then self.dismiss method will never get called because you are already popping the view controller before it.
If you want the completion block to work, you should present the ViewController instead of pushing it.Then, you can write your code in the completion block and it will execute.
I have a view controller with two buttons:
Button1 brings up the documentPickerViewController and lets user pick a file.
Button2 goes to a second view controller.
Button1 is linked to "openFile" in the code below.
Button2 calls the segue to the second view controller.
So this is how I get the problem:
Click Button1, document picker shows up.
If I pick a document, then document picker disappears and I'm back to view controller.
So far so good.
Now I press Button2. Second view controller shows up. All good. I exit and go back to 1st view controller.
Now I press Button1 again. Document picker shows up.
But this time I click "cancel". Document picker disappears but the SECOND view controller appears!
I get
"Unbalanced calls to begin/end appearance transitions for <_UIWaitingForRemoteViewContainerViewController: 0x122206480>." and
"[DocumentManager] The view service did terminate with error: Error Domain=_UIViewServiceErrorDomain Code=1 "(null)" UserInfo={Terminated=disconnect method}"
From researching I understand that I must have popped an extra 2nd view controller to the stack but I can't see where I would have done it and also where would be the appropriate place to pop it?
I've tried setting "animated: false" and that didn't make any difference.
Thanks in advance.
#IBAction func openFile(_ sender: Any) {
let documentPicker: UIDocumentPickerViewController = UIDocumentPickerViewController(documentTypes: ["public.text"], in: UIDocumentPickerMode.import)
documentPicker.delegate = self
documentPicker.modalPresentationStyle = UIModalPresentationStyle.fullScreen
self.present(documentPicker, animated: true, completion: nil)
}
func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
self.dismiss(animated: true, completion: nil)
}
func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
if controller.documentPickerMode == UIDocumentPickerMode.import {
var textRead = ""
do {
if urls.count > 0 {
for i in 0...urls.count-1 {
textRead = try String(contentsOf: urls[i], encoding: .utf8)
textView.text = textView.text + textRead
}
}
}
catch {
/* error handling here */
print("There's a problem reading the file")
}
}
}
I'm not sure what you want to do in your implementation of documentPickerWasCancelled(_:) but know that if you just want to hide the document picker, you don't need to explicitely call self.dismiss(animated: true, completion: nil): when you tap 'Cancel' the document picker dismisses itself already.
After more experimenting and researching, I found this stopped the 2nd view controller from appearing, even though the two error messages are still appearing:
func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
//self.dismiss(animated: true, completion: nil)
self.navigationController?.popToRootViewController(animated: true)
}
Would still appreciate if someone can suggest a more elegant solution which eliminates the error messages altogether.
EDIT:
After playing with it a bit more, I found the fix!
We only need this:
func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
// do nothing. The picker is dismissed anyway.
}
So the dismiss statement was causing the problem. By leaving out any dismiss picker call, the picker window closes anyway.
I am trying to building a app using the master details template.
in the Master view controller I added a button called Catalogue : this button showing a tabbar controller called Catalogue.
I don't use Segue to show the catalogue, I use the code below to show the tab controller
From Master form I called the Tabbar controller :
#IBAction func Btn_Catalogue(_ sender: Any) {
let AddCatalogueVC = self.storyboard?.instantiateViewController(withIdentifier: "CatalogueVC") as! CatalogueVC
present(AddCatalogueVC, animated: true, completion: nil)
}
From CategorieVC I use the code below to show
#IBAction func Btn_AddCategorie(_ sender: Any) {
self.Mode = "New"
let AddCategorieViewController = self.storyboard?.instantiateViewController(withIdentifier: "AddCategorieVC") as! AddCategorieVC
present(AddCategorieViewController, animated: true, completion: nil)
}
I dismiss the AddCategorieVC using the code below
#IBAction func Btn_Save(_ sender: Any)
{
if self.Txt_CategorieName.text != ""{
self.Mysave = true
self.MyCategorieName = self.Txt_CategorieName.text!
self.dismiss(animated: true, completion: nil)
}
}
I have unwind SEGUE from Save button to a function in categorieVC
#IBAction func FctSaveCategories(_ sender: UIStoryboardSegue) {
let sendervc = sender.source as! AddCategorieVC
if self.Mode == "New" && sendervc.Mysave == true { // Mode insert
let MyCategories = TblCategorie(context: Mycontext)
MyCategories.categorie_Name = sendervc.MyCategorieName
do {
try Mycontext.save()
} catch {
debugPrint ("there is an error \(error.localizedDescription)")
}
}
}
The problem is when I hit the save button in categorieVC the catalogueVC is also dismissing at the same time returning me to the master control.
I am almost sure that the problem came from the Unwind segue but I don't know why.
Update: I activate the Cancel button in AddCategorieVC with the code below
self.dismiss(animated: true, completion: nil)
and when I clicked on it only the AddCategorieVC is being dismissed and I go back to CatalogueVC. The difference between the save button and the Cancel Button is only the UNWIND segue on the Save Button.
And when I add UnWIND segue to the cancel Button (just to test the behavior) it took me back to the master form instead CatalogueVC.
How can I solve that?
And yesss I found it
It look like that unwind segue automaticly handled dismiss contrôle
So all I need to do is remove the dismiss code from the save button this way the unwind segue will took me back to catalogueVC.
.
When I dismiss an instance of MFMailComposeViewController or MFMessageComposeViewController that is presented modally from the third viewController in a navigation stack, the navigation stack is reset, and the root VC is reloaded. How can I prevent this behavior and remain on the original presenting viewController (third VC in the stack)? I get the same behavior whether I call dismiss from the presenting VC, the presented VC, or the navigationController.
This has been asked before, but I have not seen a solution.
App Structure looks like this:
TabBarController
Tab 1 - TripsNavController
-> Trips IntroductionVC (root VC) segue to:
-> TripsTableViewController segue to:
-> TripEditorContainerVC
- TripEditorVC (child of ContainerVC)
- HelpVC (child of ContainerVC)
Tab 2...
Tab 3...
Tab 4...
In the TripEditorVC I present the MFMailComposeViewController. The functions below are declared in an extension to UIViewController that adopts the MFMailComposeViewControllerDelegate protocol
func shareWithEmail(message: NSAttributedString) {
guard MFMailComposeViewController.canSendMail() else {
showServiceError(message: "Email Services are not available")
return
}
let composeVC = MFMailComposeViewController()
composeVC.setSubject("My Trip Plan")
composeVC.setMessageBody(getHTMLforAttributedString(attrStr: message), isHTML: true)
composeVC.mailComposeDelegate = self
present(composeVC, animated: true, completion: nil)
}
Then in the delegate method I dismiss the MFMailComposeVC:
public func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
switch result {
case .sent:
print("Mail sent")
case .saved:
print("Mail saved")
case .cancelled:
print("Mail cancelled")
case .failed:
print("Send mail failed")
}
if error != nil {
showServiceError(message: "Error: \(error!.localizedDescription)")
}
dismiss(animated: true, completion: nil)
}
I have tried the following to present and dismiss and get the same behavior, i.e.: the TripsNavController clears the nav stack and reloads the TripsIntroductionVC as its root VC:
self.present(composeVC, animated: true, completion: nil)
self.parent?.present(composeVC, animated: true, completion: nil)
self.parent?.navigationController?.present(composeVC, animated: true, completion: nil)
self.navigationController?.present(composeVC, animated: true, completion: nil)
You can also check with presentingViewController?.dismiss method to get the solution.
I have tried with following navigation stack.
I am able to send email successfully from Container VC's Send Email button using your code only.
Can you please check and verify navigation flow?
Please let me know if you still face any issue.
dismiss(animated: true, completion: nil)
to
self.dismiss(animated: true, completion: nil)
Try this
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let secondViewController = storyboard.instantiateViewControllerWithIdentifier("secondViewControllerId") as! SecondViewController
self.presentViewController(secondViewController, animated: true, completion: nil)
or
https://stackoverflow.com/a/37740006/8196100
Just Use Unwind Segue its Pretty simple and perfect in your case
I have used many times..
just look at this Unwind segue's example
. If u still don't able to find answer or not able to understand the Unwind segue then just reply to me.
Hope this will solve your problem.
I found the problem with my navigation stack today. I built a simple
project that duplicated the tabBarController/NavigationControler architecture of my problem project, component by component, until dismissing a MFMailComposeViewController caused my navigation stack to reset as described in my original post.
That immediately pointed to the source of the bug. In my subclassed UINavigationCotroller I was instantiating the root viewController in code so that I could skip an introductory view if the user had set a switch in the apps settings. In order to pick up changes in that switch setting I was calling my instantiation code in viewDidAppear of the navigationController. That worked fine EXCEPT when dismissing the mailComposeVC. The fix was to add a guard statement in viewDidAppear to return if the navControllers viewController collection was not empty, and send and respond to an NSNotification when the switch was changed.
class TopNavigationController: UINavigationController {
var sectionType: SectionType?
var defaults = UserDefaults.standard
var showIntroFlag: Bool = true
override func viewDidLoad() {
super.viewDidLoad()
// Handle initial load of the tab bar controller where we are not sent a sectionType
if sectionType == nil {
sectionType = .groups
}
setShowIntroFlag()
NotificationCenter.default.addObserver(self, selector: #selector(resetControllers), name: NSNotification.Name(rawValue: "kUserDidChangeShowIntros"), object: nil)
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(true)
guard self.viewControllers.isEmpty else {
return
}
loadControllers()
}
func setShowIntroFlag() {
showIntroFlag = true
// Check NSUserDefaults to see if we should hide the Intro Views for all sections
if defaults.bool(forKey: "SHOW_SECTION_INTROS") == false {
showIntroFlag = false
}
}
func loadControllers() {
if showIntroFlag == true {
showIntro()
} else {
skipIntro()
}
}
func resetControllers() {
setShowIntroFlag()
loadControllers()
}
I have an app which is a single view application. I have a navigation controller linked up to all child controllers from the root view controller.
In each child controller, I have a logout button. I'm wondering if I can have a single function I can call which will dismiss all the controllers which have been open along along the way, no matter which controller was currently open when the user presses logout?
My basic start:
func tryLogout(){
self.dismissViewControllerAnimated(true, completion: nil)
let navigationController = UINavigationController(rootViewController: UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier("LoginViewController") )
self.presentViewController(navigationController, animated: true, completion: nil)
}
I am looking for the most memory efficient way of carrying out this task. I will put my logout function in a separate utils file, but then I can't use self. And I still have the issue of knowing which controllers to dismiss dynamically.
Update
Pop to root view controller has been suggested. So my attempt is something like:
func tryLogout(ViewController : UIViewController){
print("do something")
dispatch_async(dispatch_get_main_queue(), {
ViewController.navigationController?.popToRootViewControllerAnimated(true)
return
})
}
Would this be the best way to achieve what I'm after?
You can call :
self.view.window!.rootViewController?.dismiss(animated: false, completion: nil)
Should dismiss all view controllers above the root view controller.
Updated answer for Swift 4 and swift 5
UIApplication.shared.keyWindow?.rootViewController?.dismiss(animated: true, completion: nil)
and when you use navigationController
self.navigationController?.popToRootViewController(animated: true)
Works for Swift 4 and Swift 5
To dismiss any unwanted residue Modal ViewControllers, I used this and worked well without retaining any navigation stack references.
UIApplication.shared.keyWindow?.rootViewController?.dismiss(animated: false, completion: nil)
self.view.window! did crash for my case possibly because its a Modal screen and had lost the reference to the window.
Swift3
navigationController?.popToRootViewControllerAnimated(true)
Take a look at how unwind segues work. Its super simple, and lets you dismiss/pop to a certain viewcontroller in the heirarchy, even if it consists of a complex navigation (nested pushed and or presented view controllers), without much code.
Here's a very good answer (by smilebot) that shows how to use unwind segues to solve your problem
https://stackoverflow.com/a/27463286/503527
To dismiss all modal Views.
Swift 5
view.window?.rootViewController?.dismiss(animated: true, completion: nil)
If you have a customed UITabbarController, then try dismiss top viewController in UITabbarController by:
class MainTabBarController: UITabBarController {
func aFuncLikeLogout() {
self.presentedViewController?.dismiss(animated: false, completion: nil)
//......
}
}
If you have access to Navigation Controller, you can try something like this. Other solutions didn't work for me.
func popAndDismissAllControllers(animated: Bool) {
var presentedController = navigationController?.presentedViewController
while presentedController != nil {
presentedController?.dismiss(animated: animated)
presentedController = presentedController?.presentedViewController
}
navigationController?.popToRootViewController(animated: animated)
}
works for Swift 3.0 +
self.view.window!.rootViewController?.dismiss(animated: true, completion: nil)
I have figured out a generic function to dismiss all presented controllers using the completion block.
extension UIWindow {
static func keyWindow() -> UIWindow? {
UIApplication.shared.windows.filter({ $0.isKeyWindow }).first
}
}
func getVisibleViewController(_ rootViewController: UIViewController?) -> UIViewController? {
var rootVC = rootViewController
if rootVC == nil {
rootVC = UIWindow.keyWindow()?.rootViewController
}
var presented = rootVC?.presentedViewController
if rootVC?.presentedViewController == nil {
if let isTab = rootVC?.isKind(of: UITabBarController.self), let isNav = rootVC?.isKind(of: UINavigationController.self) {
if !isTab && !isNav {
return rootVC
}
presented = rootVC
} else {
return rootVC
}
}
if let presented = presented {
if presented.isKind(of: UINavigationController.self) {
if let navigationController = presented as? UINavigationController {
return navigationController.viewControllers.last!
}
}
if presented.isKind(of: UITabBarController.self) {
if let tabBarController = presented as? UITabBarController {
if let navigationController = tabBarController.selectedViewController! as? UINavigationController {
return navigationController.viewControllers.last!
} else {
return tabBarController.selectedViewController!
}
}
}
return getVisibleViewController(presented)
}
return nil
}
func dismissedAllAlert(completion: (() -> Void)? = nil) {
if let alert = UIViewController.getVisibleViewController(nil) {
// If you want to dismiss a specific kind of presented controller then
// comment upper line and uncomment below one
// if let alert = UIViewController.getVisibleViewController(nil) as? UIAlertController {
alert.dismiss(animated: true) {
self.dismissedAllAlert(completion: completion)
}
} else {
completion?()
}
}
Note: You call anywhere in code at any class
Use:-
dismissedAllAlert() // For dismiss all presented controller
dismissedAllAlert { // For dismiss all presented controller with completion block
// your code
}
Swift
Used this to jump directly on your ROOT Navigation controller.
self.navigationController?.popToRootViewController(animated: true)