I'm creating an application where I place a view controller ontop of another with
Presentation: current context
But when I'm trying to dismiss the screen by dragging the top towards the bottom the view does not disappear.
I've also tried to add a button to make it dismiss but that doesn't work either.
#IBAction func dis(_ sender: Any) {
navigationController?.popViewController(animated: true)
self.dismiss(animated: true)
}
So, how can I dismiss both views when dragging the top one down when it uses "current context" as presentation style?
I'm using "current context" because the previous screen should never be displayed again. And instead of dragging down both, I would like to drag down just one to make both of them disappear. But it does not seem to work as expected.
Although "current context" is not for this purpose as #matt mentioned,
You should dismiss the controller who presents this one to dismiss both together in this case:
self.presentingViewController!.dismiss(animated: true) // `!` is to makeing sure it's not crashing.
Demo:
Use this simple code to demo:
class ViewController: UIViewController {
#IBAction func present() {
let destination = storyboard!.instantiateInitialViewController()!
if presentingViewController != nil {
// You are not in the A
if presentingViewController?.presentingViewController != nil {
// You are in the C
presentingViewController?.presentingViewController?.dismiss(animated: true)
return
} else {
// You are in the B
destination.modalPresentationStyle = .currentContext
}
}
present(destination, animated: true, completion: nil)
}
}
Usage:
Create a single view application
Drag a button into the view controller
Replace the ViewController class with the provided code
Connect the #IBAction
Run it to see the result.
If you use fullscreen presentation (so that there is no drag-to-dismiss) it's quite simple to do this with essentially no code at all.
Note that the yellow view controller appears as an intermediary when presenting, but not when dismissing.
Related
In Start Developing iOS Apps (Swift): Implement Edit and Delete Behavior
, The offical tutorial tell me should use presentingViewController and navigationController to indicate the specified view is Edit or Show, Like following code:
#IBAction func cancel(_ sender: UIBarButtonItem) {
// Depending on style of presentation (modal or push presentation), this view controller needs to be dismissed in two different ways.
let isPresentingInAddMealMode = presentingViewController is UINavigationController
if isPresentingInAddMealMode {
dismiss(animated: true, completion: nil)
}
else if let owningNavigationController = navigationController{
owningNavigationController.popViewController(animated: true)
}
else {
fatalError("The MealViewController is not inside a navigation controller.")
}
}
The adding view is presented by modal, the editing view is presented by embed navigation controller, But I think this approach is not good to understand and easy maintain, How about introduce a isEditOrShow instance varible in the view to indicate the state? like following:
#IBAction func cancel(_ sender: UIBarButtonItem) {
// Depending on style of presentation (modal or push presentation), this view controller needs to be dismissed in two different ways.
if isEditingOrShow = .edit{
dismiss(animated: true, completion: nil)
}
else isEditingOrShow = .show{
owningNavigationController.popViewController(animated: true)
}
}
The tutorial explains that, there are two ways in which you can dismiss view controllers.
For example, when you present a view controller as modal, you can use the below code to dismiss it.
dismiss(animated: true, completion: nil)
However, if you are using a push presentation (Navigation controller), then you should use the below code to dismiss it.
owningNavigationController.popViewController(animated: true)
How about introduce a bool isEditOrShow instance varible in the view to indicate the state?
From what I understand, you won't be needing isEditOrShow variable. If you have any questions, let me know.
This question already has answers here:
Dismissing multiple modal view controllers at once?
(7 answers)
Closed 4 years ago.
I recreated the question and describe its essence more precisely.
I have two view controllers presented modally on Swift 4, without storyboard (can't use unwind) and without navigation controller
A presents B which presents C.
The reason why we don't use navigation controller, it's because we what simple animation from bottom to top and instead of breaking the standard animation from right to left, we decided to use present.
I would like to dismiss 2 view controllers and go from C to A.
Please, don't mark this question as duplicate before you read my question carefully. I found a tone of similar post, but neither solved my problem. Some of them Objective-C or some of the suggest to use:
self.presentingViewController?.presentingViewController?.dismiss(animated: true, completion: nil)
Or:
self.presentingViewController?.dismiss(animated: false, completion: nil)
self.presentingViewController?.dismiss(animated: true, completion: nil)
It's works, but it create weird animation. It's just delete C and animate dismiss for B:
Expected result:
Idea: you need to dismiss third controller with animation and after dismissing you need to dismiss second without animation. While third controller is being dismissed, second shouldn't be visible.
First, set Presentation style of second view controller to Over Current Context when you're presenting it (since we will need to hide its view when we will dismiss third controller)
let vc2 = VC2()
vc2.modalPresentationStyle = .overCurrentContext
present(vc2, animated: true)
continue with creating callbacks properties for willDismiss and didDismiss inside third controller. This callback will be called before and after you dismiss third controller
class VC3: UIViewController {
var willDismiss: (() -> Void)?
var didDismiss: (() -> Void)?
#IBAction func dismissButtonPressed(_ sender: UIButton) {
willDismiss?()
dismiss(animated: true) {
self.didDismiss?()
}
}
}
then in second view controller in the place where you present third view controller, set third controller's callback properties: declare what happens when third controller will dismiss: you need to hide view of second and then after dismissing third you need to dismiss second without animation (view can stay hidden since view controller will be deinitialized)
class VC2: UIViewController {
#objc func buttonPressed(_ sender: UIButton) {
var vc3 = VC3()
vc3.willDismiss = {
self.view.isHidden = true
}
vc3.didDismiss = {
self.dismiss(animated: false)
}
present(vc3, animated: true)
}
}
Anyway, second option is using UINavigationController and then just call its method popToViewController(_:animated:).
Create a snapshot from the currently visible view and add it as a subview to the first presented view controller. To find that you can simply "loop through" the presenting view controllers and dismiss from the initial one:
#IBAction func dismissViewControllers(_ sender: UIButton) {
var initialPresentingViewController = self.presentingViewController
while let previousPresentingViewController = initialPresentingViewController?.presentingViewController {
initialPresentingViewController = previousPresentingViewController
}
if let snapshot = view.snapshotView(afterScreenUpdates: true) {
initialPresentingViewController?.presentedViewController?.view.addSubview(snapshot)
}
initialPresentingViewController?.dismiss(animated: true)
}
This is the result with slow animations enabled for the dismissal:
https://www.dropbox.com/s/tjkthftuo9kqhsg/result.mov?dl=0
If you are not using a navigation controller and you want to dismiss all ViewControllers to show the root ViewController (assuming A is the root):
self.view.window?.rootViewController?.dismiss(animated: true, completion: nil)
Use this in button action method.
The current VC will dismiss when you dismiss the parent VC.
This will dismiss both VCs in single animation.
self.presentingViewController?.presentingViewController?.dismiss(animated: true, completion: nil)
I have a Tab bar in the first view and a total of two views.
However, when I move from the first view to the second view and then back to the first view using the Segue, the Tab bar of the first view disappears.
When return to the first view from the second view, what is the way the Tab bar does not disappear?(without using unwind)
Don't use unwind segue here. When you need to get back to previous ViewController, just dismiss your current ViewController
dismiss(animated: true, completion: nil) /* call this in second VC */
I suggest you read the documentation for understanding how combined View Controller Interfaces. Anyway, if you need to pop to previous view controller on the flow, you need to use
navController.popViewController(animated: true)
But, if the need to pop up on the specific ViewController on the queue of View Controllers in the NavigationViewController, you need to use
navController.popToViewController(ViewController, animated: true)
From the moment you are using a NavigationController, a return button will automatically appear on the UINavigationBar, so you do not have to worry about that. Unless you want to customize the back buttons in the viewcontrollers queue, in this case use the above methods.
It's for page 1. Display tabBarController once page is loaded.
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
self.tabBarController?.tabBar.hidden = true
}
If click event is fired, hide tabBarController.
override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!) {
if (segue.identifier == "twoSegue") {
self.tabBarController?.tabBar.hidden = false
}
}
I'm currently learning the very basics of Swift, having just finished the iOS Application Development Tutorial from the Apple Developer website.
I am wanting to create a swipe gesture that's very similar to most popular applications that are out at the moment. Swipe right to reveal the content from another view from the left, essentially a 'back' button but with a gesture instead.
Here is an image I found of the gesture I want to create:
The tutorial from Apple explains how the cancel button works in the navigation controller:
//MARK: Navigation
#IBAction func cancel(_ sender: UIBarButtonItem) {
// Depending on style of presentation (modal or push presentation), this view controller needs to be dismissed in two different ways.
let isPresentingInAddMealMode = presentingViewController is UINavigationController
if isPresentingInAddMealMode {
dismiss(animated: true, completion: nil)
}
else if let owningNavigationController = navigationController {
owningNavigationController.popViewController(animated: true)
}
else {
fatalError("The MealViewController is not inside a navigation controller.")
}
}
And so (referencing the tutorial from Apple) I placed a Swipe Gesture Recogniser object on the 'New Meal' controller and created my own 'rightSwipe' function that does the exact same thing:
#IBAction func rightSwipe(_ sender: UISwipeGestureRecognizer) {
// Depending on style of presentation (modal or push presentation), this view controller needs to be dismissed in two different ways.
let isPresentingInAddMealMode = presentingViewController is UINavigationController
if isPresentingInAddMealMode {
dismiss(animated: true, completion: nil)
}
else if let owningNavigationController = navigationController {
owningNavigationController.popViewController(animated: true)
}
else {
fatalError("The MealViewController is not inside a navigation controller.")
}
}
This works great, the application at the moment is clever enough to recognise your 'entry' to the view (whether it's via tapping on an existing item on the list or via the 'create a new item' view).
Is it now possible to control the animation with your finger instead of executing the entire thing as soon as the screen has been swiped to the right? This is a little difficult to explain...
As soon as I swipe right, the animation gets executed and the current view is dismissed. I have no control over the animation until it is over. I'm not able to animate the 'dismissal' with my finger as I drag it across the screen.
The scenario I want to explain is very similar to how switching pages on the home screen of iOS works.
I want to be able to 'hold' the screen on the left, be able to drag it to the right, while holding down, and should be able to see the previous view as I do it, then execute the actual transition of views as soon as I let go. I hope you understand what I mean?
How can this be achieved? Is there anything currently built in that allows me to do this? Would anyone be able to show me how this can be done?
I'm currently working with Swift 3 and using the Xcode9-beta IDE
I am trying to make a splash screen. I have a view that has a background image being drawn onto it and then another view I want to transition to after a few seconds. I am trying to use the following code:
self.performSegueWithIdentifier("showApp", sender: self)
I created a segue between the two views by ctrl+dragging a line from one to the other. I set the segue's identifier to "showApp".
When I run the code nothing happens and there are no errors. Any ideas?
Here is the controller for the splash screen:
class SplashViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
sleep(2)
// THIS DOES NOTHING:
self.performSegueWithIdentifier("showApp", sender: self)
// THIS AS SUGGESTED ALSO DOES NOTHING:
var otherViewController:UIViewController = self.storyboard.instantiateViewControllerWithIdentifier("test") as UIViewController
self.presentViewController(otherViewController, animated: true, completion: nil)
}
}
Normally, you need a navigation controller in order to use segue.
Highlight your SplashViewController object inside the Storyboard and go to
Editor -> Embeded In -> Navigation Controller
After that, remove the code suggested by Clement and try running the project again, you should get the result that you expected.