Using storyboard , I'm invoking a segue (set type to modal) in order to display the second controller , and the same way to display the third controller. A->B->C. I expect dismiss B and C together , and return to A. There was no navigation view controllers , no popToRootViewControllerAnimated: .
In docs:
If you present several view controllers in succession, thus building a stack of presented view controllers, calling this method on a view controller lower in the stack dismisses its immediate child view controller and all view controllers above that child on the stack. When this happens, only the top-most view is dismissed in an animated fashion; any intermediate view controllers are simply removed from the stack. The top-most view is dismissed using its modal transition style, which may differ from the styles used by other view controllers lower in the stack.
I tried a variety of ways but failed. Am I missing something really simple ?
Try This
[self.presentingViewController.presentingViewController dismissModalViewControllerAnimated:YES]
Also try This
[self.parentViewController.parentViewController dismissModalViewControllerAnimated:YES];
Related
I'm working on a project which has multiple view controllers stacked in a navigation controller, similar to this:
https://youtu.be/yl2m4fDOLQo
I fear that I may end up stacking too many view controllers in one navigation controller. I understand that once there are more than 3 view controllers stacked in a navigation controller, the views are presented "modally"
First of all, what is a "modal" presentation? I looked it up in Swift documentation but I'm having some trouble understanding how it differs from the navigation stack. Second, if there is a problem, is there any way around it?
I'm new to this so help is much appreciated,
Nick
I understand that once there are more than 3 view controllers stacked in a navigation controller, the views are presented "modally"
This is false. You can have as many view controllers in a navigation stack as your app needs, as long as the device has enough memory. View controllers in a navigation stack have a navigation bar (technically, this is part of the navigation controller), a back button and (hopefully) a swipe-right gesture that allow the user to go back "up" the stack. You add a view controller to the stack by calling pushViewController(animated:) and remove it by calling popViewController(animated:) on the navigation controller.
A modal view controller exists outside of the navigation stack. It does not have a navigation bar because it's not in a navigation controller. You are responsible for adding some way to dismiss the modal, such as tapping a close button placed manually in the view controller's view somewhere. You can even add a navigation bar instance manually and put a close button in it. You show a modal by calling present(_:animated:completion:) on the currently-displayed view controller and dismiss it by calling dismiss(_:animated:completion:).
I have three view controllers, say A, B and C. I am navigating through this views like follows;
A -presenting-> B -presenting-> C -presenting-> B
And from B, if I dismiss I want to navigate to C. But instead of that, now it is moving to A. I can't use dismiss for navigation from C to B (some internal issues). So how can I fix this? Please help.
You hit into a limitation of dismissModalViewController: it will remove all of your modal views (source):
If you present several view controllers in succession, and thus build a stack of presented view controllers, calling this method on a view controller lower in the stack dismisses its immediate child view controller and all view controllers above that child on the stack. When this happens, only the top-most view is dismissed in an animated fashion; any intermediate view controllers are simply removed from the stack. The top-most view is dismissed using its modal transition style, which may differ from the styles used by other view controllers lower in the stack.
What you could do is using a UINavigationController and simply push/pop controllers on to it according to your requirements.
Alternatively, you could simply display the views managed by the various controllers you have by directly calling addSubview on your top view and making sure they cover the whole screen and that the managing controller is correctly retained/released (the view is automatically when you add/remove it to another view).
As a hint, you could do it like this:
where you have presentModal..., use addSubview;
where you have dismiss..., use removeFromSuperview;
store a reference to any view controller whose view you manage like I suggest here in retain/strong property.
Hi use the below code in "C" viewcontroller
[[[self presentingViewController] presentingViewController] dismissModalViewControllerAnimated:YES];
i'm developing an app for iphone, and i use
[self presentModalViewController:aViewControllerInitializateBefore animated:YES];
Can you tell me what happens to the current viewController when i use this?
The current view controller stays "underneath" the modal view controller and will reappear when you call
- (void)dismissModalViewControllerAnimated:(BOOL)animated
either on the modal view or the parent/presenting view controller (as the parent/presenting view controller's view is no longer visible, it's view may be unloaded when the system requires memory, and reloaded on dismiss).
From this method's documentation:
The parent view controller is responsible for dismissing the modal
view controller it presented using the
presentModalViewController:animated: method. If you call this method
on the modal view controller itself, however, the modal view
controller automatically forwards the message to its parent view
controller.
If you present several modal view controllers in succession, and thus
build a stack of modal view controllers, calling this method on a view
controller lower in the stack dismisses its immediate child view
controller and all view controllers above that child on the stack.
When this happens, only the top-most view is dismissed in an animated
fashion; any intermediate view controllers are simply removed from the
stack. The top-most view is dismissed using its modal transition
style, which may differ from the styles used by other view controllers
lower in the stack.
Also note the change in iOS 5
Prior to iOS 5.0, if a view did not have a parent view controller and
was being presented modally, the view controller that was presenting
it would be returned. This is no longer the case. You can get the
presenting view controller using the presentingViewController
property.
After a modal view controller is dismissed, is there any delegate method called to bring the parent view controller to the front?
I ended up using delegation from Apple's View Controller Programming Guide for iOS :
http://developer.apple.com/library/ios/#featuredarticles/ViewControllerPGforiPhoneOS/ModalViewControllers/ModalViewControllers.html#//apple_ref/doc/uid/TP40007457-CH111-SW14
When it comes time to dismiss a modal view controller, the preferred approach is to let the parent view controller do the dismissing. In other words, the same view controller that presented the modal view controller should also take responsibility for dismissing it whenever possible. Although there are several techniques for notifying a parent view controller that it should dismiss its modally presented child, the preferred technique is delegation.
There was a good example in the CoreDataRecepies sample code when adding a recipe that fit what I was trying to do.
i.e., at the "same time" view[Will|Did]Disappear: is being called on the modal view controller as its view is being dismissed, the view[Will|Did]Appear: are sent to the view controller that is being revealed
the code in here should not really need to differ from the reveal code you used when it was first displayed,
if you need data passed back from the modal controller to the one that displayed it, generally the code that dismisses the modal controller lets the other one know
parentController.item = self.chosenItem;
[parentController dismissModal…
My application presents a modal view (A) from the main view that lets the user make a selection. When they make that selection it opens a second modal view (B) on top of the first one (A).
When I'm done with the second modal view (B), and want to dismiss it, I would like to dismiss the first one (A) and the second one (B) at the same time as I no longer need the user to return to that one (A) either.
The only thing I came up with is:
[self.parentViewController.parentViewController.parentViewController. dismissModalViewControllerAnimated:YES];
It works, but it just doesn't look correct. Is this OK to do or is there a more accepted way to do this?
I don't think that your way is wrong. It is what Apple documentation recommends:
If you present several modal view controllers in succession, and thus build a stack of modal view controllers, calling this method on a view controller lower in the stack dismisses its immediate child view controller and all view controllers above that child on the stack. When this happens, only the top-most view is dismissed in an animated fashion; any intermediate view controllers are simply removed from the stack. The top-most view is dismissed using its modal transition style, which may differ from the styles used by other view controllers lower in the stack.
(UIApplication.sharedApplication().delegate! as! AppDelegate).navigationController?.viewControllers.first?.dismissViewControllerAnimated(true, completion: nil)