Im trying to dismiss a ModaViewController called C, back to A. The ModalViewController is presented in B. Therefore the Navigation flow is A->B - (present ModalView) -> C. I am able to dismiss the ModalViewController back to B, but I am unable to pop back to A in the completion bracket. This is the code I have tried:
[self dismissViewControllerAnimated:YES completion:^{
[self.navigationController popToViewController:[[self.navigationController viewControllers] objectAtIndex:0] animated:YES];
}];
The ModalViewController is dismissed but does not pop back to A. I call this block of code in an IBAction.
Any advice?
On a second note, when I dismiss the ModalViewController all my UIPickers in Controller B are empty/ deallocated. I am using ARC as well.
The problem with your code is that self.navigationController will be nil. If you have a controller (A) embedded in a navigation controller, and that controller pushes to another controller (B) which then presents your last controller (C), then you need to do something like this,
-(IBAction)dismissToBThenPop:(id)sender {
UINavigationController *nav = (UINavigationController *)self.presentingViewController;
[self dismissViewControllerAnimated:YES completion:^{
[nav popViewControllerAnimated:YES];
}];
}
Even though you present C from B, the actual presentingViewController will be the navigation controller. This code will dismiss C then pop B, but you will see B for an instant before ut pops back to A. If you don't want to see this, then you should use an unwind segue to go directly back to A from C.
Your second problem about the pickers being empty and deallocated should not be happening under the scenario that you say you have. You will have to provide more information about what you're doing in B to solve that problem.
Create a protocol in ModalViewController, let's say ModalViewControllerDelegate with a method -(void)dismissTheModal, and make B implement this protocol. Before showing the ModalViewController, do modalViewController.delegate = self. When you're IBAction is called, do [self.delegate dismissTheModal], and in controller B you should do :
-(void)dismissTheModal {
[self dismissViewControllerAnimated:YES completion:^{
[self popViewController];
}];
Related
Let's say I have 3 controllers (A, B, C). A and C is ViewControllers, B is NavigationController. Normal application flow is A as root view, A present (modal) B, B push C.
What I want is to present C as top view controllers without going through all the animation from A-B-C but still have the hierarchy (means C can go back to A), is it possible?
We can set window rooViewController directly to C but it wont have the hierarchy
EDIT:
Maybe my question isnt clear enough, the main point here is, when I open my app, I want to show C directly but still have A->B->C view hierarchy so I can go back to A via normal pop and dismiss
EDIT2:
I manage to show C with B-C hierarchy, so I can pop back to B from C. Now my problem is how can I present B (NavigationController) from A (ViewController) so when I close B it will **dismiss* to A
EDIT3:
I saw some answer that use NavigationController, it works BUT not what I want because normally from A to B I use modal presentViewController and from B to A I use dismissViewController
EDIT4:
So far what I got is
self.window.rootViewController = vcA;
[self.window makeKeyAndVisible];
[vcA presentViewController:vcB animated:NO completion:nil];
[vcB pushViewController:vcC animated:NO];
this will give correct hierarchy that I want but it give fast animation (a blink) showing A and than C and also give warning Unbalanced calls to begin/end appearance transitions for <vcA: 0x7fcfa0cf9c50>.
EDIT5:
I endup ignoring the warning and stick with my prev answer (but still welcome for another solution). And for the blinking problem I use workaround below
uiview *overlay = [new uiview]; // using vcA.frame
overlay.backgroundColor = white; // I use dominant color of vcC
vcA addSubview:overlay;
self.window.rootViewController = vcA;
[self.window makeKeyAndVisible];
[vcA presentViewController:vcB animated:NO completion:^{
[overlay removeFromSuperview];
}];
[vcB pushViewController:vcC animated:NO];
This will disguise the blinking behavior so no one will notice (I hope :-p)
Use a UINavigationViewController and then call
setViewControllers(_:animated:)
Use this method to update or replace the current view controller stack without pushing or popping each controller explicitly. In
addition, this method lets you update the set of controllers without
animating the changes, which might be appropriate at launch time when
you want to return the navigation controller to a previous state.
If animations are enabled, this method decides which type of
transition to perform based on whether the last item in the items
array is already in the navigation stack. If the view controller is
currently in the stack, but is not the topmost item, this method uses
a pop transition; if it is the topmost item, no transition is
performed. If the view controller is not on the stack, this method
uses a push transition. Only one transition is performed, but when
that transition finishes, the entire contents of the stack are
replaced with the new view controllers. For example, if controllers A,
B, and C are on the stack and you set controllers D, A, and B, this
method uses a pop transition and the resulting stack contains the
controllers D, A, and B.
Let me know if it help you :)
push A and B and C like you normally would but do it by using presentViewController:? animated:NO and pushViewController:? animated:NO -- not animating is the clue
e.g. (mock code)
applicationDidFinishLaunching {
id a = [MyA new]; //root, presents b
id b = [MyA new]; //pushes c you said.. so it is or has a navigationController
id c = [MyA new];
[a presentViewController:b animated:NO];
b.navigationController pushViewController:c animated:NO];
}
To segue to any ViewController you want to: Have you drawn a custom segue in the storyboard by holding down the control key on your keyboard and clicking the ViewController you want the segue to be in? While still holding control, you can drag it to the viewcontroller you want to segue to. After that just let go and XCode will let you choose the type of segue you want: push, modal, or custom.
After that, click the visual segue reference that Xcode creates (looks like a big grey arrow in the storyboard that points to your viewcontrolelrs) and click the attributes inspector. Then look where it says identifier. From there you can name the segue anything you want and reference it programmatically. Just do the above and call the below message and you should be able to go to any viewcontroller when ever you want to.
[self performSegueWithIdentifier:#"ShowViewControllerA" sender:self];
Also, I agree with everyone else saying to set Viewcontroller C as root ViewController in the storyboard. PresentViewController is also a good idea. etc
Follow #Daij-Djan's answer:
applicationDidFinishLaunching {
id a = [MyA new]; //root, presents b
id b = [MyA new]; //pushes c you said.. so it is or has a navigationController
nav d = [[Nav alloc] initWithRoot:b];
id c = [MyA new];
[a presentViewController:d animated:NO];
b.navigationController pushViewController:c animated:NO];
}
Why don't you just present C on top of A with presentViewController?
EDIT:
A -> C:
In vcB I would add a boolean property indicating whether we are in the mentioned flow and present vbB in vcA this way:
// We are in vcA where you want to present vcB and vcC
vcB.transient = YES;
[vcA presentViewController:vcB animated:NO completion:^{
[vcB pushViewController:vcC animated:NO];
}];
C -> A
When you want to go back to vcA, popping vcC will call viewDidAppear in vcB.
// We are in vcB
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
if(self.transient == YES) {
[self dismissViewControllerAnimated:NO completion:nil];
return;
}
}
With this solution when you go back from vcC to vcA you will temporary see vcB, as we have to wait for viewDidAppear to be called.
EDIT 2:
Alternatively if you don't need to directly go back from vcC to vbA, just use the first piece of code (no transient property required).
Keep A as rootVC(in applicationDidFinishLaunching). So when you open your app it will load A first.
Once A is loaded(in viewDidLoad) call a method to present B(keep animation = NO while presenting).
When B is loaded, call a method to push to C(keep animation = NO while pushing).
Hope this helps!
I have a ViewController, HomeVC, who manages the transition between three other view controllers, PhotopickerVC, CroppingVC and EditingVC.
As HomeVC dismisses one VC and presents another VC, I get an undesired effect in which HomeVC is visible for a fraction of a second between these transitions.
Here is a little more details about my code.
The normal flow of the app is HomeVC → PhotopickerVC → CroppingVC → EditingVC (both PhotopickerVC and CroppingVC are only assisting in getting to the final EditingVC, they are no longer required after they are dismissed).
I implement this flow using segues from the HomeVC in the following form:
Starting from HomeVC visible, Photo button is pressed, a (subclassed) UIImagePickerController is created and presented.
When photo was chosen, (subclassed) UIImagePickerController calls [picker dismissViewControllerAnimated:NO completion:nil]; This takes us back to HomeVC
In HomeVC method viewWillAppear, I call [self performSegueWithIdentifier:#"CroppingVC" sender:self];
In CroppingVC, when user presses Accept button, CroppingVC calls [self dismissViewControllerAnimated:NO completion:nil]; This takes us back to HomeVC
In HomeVC viewWillAppear, I call [self performSegueWithIdentifier:#"EditingVC" sender:self];
In EditingVC, when the user presses Home, EditingVC calls [self dismissViewControllerAnimated:YES completion:nil]; This takes us back to HomeVC.
From what I see, you do not really need the HomeVC to manage transitions. What you should do, is to make the VC hierarchy exactly as you wrote:
HomeVC → PhotopickerVC → CroppingVC → EditingVC
The arrows should be eg. push segues, and then in the prepareForSegue method you can just pass all the necessary parameters.
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
YourViewController *destinationController = (YourViewController *)segue.destinationViewController;
// do sth
}
This way you can achieve nice and smooth transitions. The way your application is now seems to have a structural flaw, because as you have said, when a ViewController gets used once, it is not needed anymore. After that you can just return to the HomeVC.
WLINewPostViewController *newPostViewController = [[WLINewPostViewController alloc] initWithNibName:#"WLINewPostViewController" bundle:nil];
UINavigationController *newPostNavigationController = [[UINavigationController alloc] initWithRootViewController:newPostViewController];
newPostNavigationController.navigationBar.translucent = NO;
[tabBarController presentViewController:newPostNavigationController animated:YES completion:nil];
So I just simply push a new UIViewController.
Then after it posts the server callback calls a method with this code from the WLINewPostViewController.m:
[self dismissViewControllerAnimated:YES completion:^{
NSLog(#"Completed");
}];
[[self navigationController] popViewControllerAnimated:YES];
if (self == self.navigationController.visibleViewController){
NSLog(#"self = visibile");
}
if (self == self.presentingViewController.presentingViewController){
NSLog(#"self = presenting");
}
}
I tried a bunch of different things and none work.
I am relatively new to Xcode but after trying
[self dismissViewControllerAnimated:YES completion]
[self.navigationController popViewControllerAnimated:YES]
[self.navigationController.visibleViewController.presentedViewController dismissViewControllerAnimated:YES completion:nil];
[self.navigationController dismissViewControllerAnimated:YES completion:nil];
and every other possibility, I am officially stumped. The WLINewPostViewController still won't dismiss.
It Logs out "self = visible"
Let me illustrate what you are trying to do
You have a navigation controller with Controller A.
Here you are trying to present another Controller B from Controller A.
Now when you get a callback from the server, you should call dismissViewControllerAnimated from Controller B to dismiss itself.
So after dismissViewControllerAnimated:completion: method call, the Controller B will be dismissed and Controller A will be shown automatically. Now you do not need to call popViewControllerAnimated: in completion block again as there is no other Controller in navigation controller to load.
If you have different use case, let me know I can provide solution.
You are presenting a view over navigationbar instead of pushing it over navigationbar.
When push you pop. When you present you dismiss. So instead of popViewControllerAnimated you need to use dismissViewControllerAnimated:completion
dismiss behaves differently depending on the receiver. From the docs:
The presenting view controller is responsible for dismissing the view controller it presented. If you call this method on the presented view controller itself, it automatically forwards the message to the presenting view controller.
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.
In short, if the vc on top calls it on itself, it dismisses itself. Anywhere else on the stack dismisses to that point, animating only the topmost vc.
What's extra confusing (for you and many others) is that the navigation vc has a stack too, and your problem is complicated further by presenting an navigation vc atop a tab-bar vc.
So what to do? The question is unclear about which vc is the receiver in the posted code (who is self in that snippet?). The text implies that self is a vc on the stack of the presented navigation vc, like...
TabBarVC --- presents ---> NavVC
| |
| --- viewControllers stack = rootVC, vc1
|
---> viewControllers for each tab
... and it's root or vc1 that wants to dismiss. If I'm right about that, then, given the docs, the solution is clear:
[self.navigationController dismissViewControllerAnimated:YES completion:^{}];
will put us back on the tabbar vc on whatever tab was visible when we did the present.
I have 3 view controllers, A, B and C. B is presented on A. What I need is to present C on A when a button clicked on B and dismiss B. But I am unable to do so. Is there some workaround.
Thanks for help.
click the button on B, in iOS5,
UIViewController *presentingVC = self.presentingViewController;
[self dismissViewControllerAnimated:YES completion:^{
[presentingVC presentViewController:vc3 animated:YES completion:nil];
}];
when you clicked the button on B, pop B itself and use NSNotificationCenter to gave a notification to A,make A to push C.
If you don't want to setup a delegate just get A through the property presentingViewController inside B, call the desired method of A, in that method first dismiss modal controller and then present C.
i have a uivewcontroller (let's call it A) that loads uiviewcontroller (B) setting it up as a delegate which i use to close B and continue code on A. There is also a scenerio where B leads to another uiviewcontroller C (again with a delegate). When C is closed i use it's delegate to return to B but in this scenario i also want B to be immediately dismissed and the code to return to A. Now, B->A works, and C->B works but doing C->B->A fails at B with an error:
"attempt to dismiss modal view controller whose view does not currently appear" it appears to be trying to dismiss view C again.
Both viewcontrollers are being dismissed with this code (though the code sits in different uiviewcontrollers)
[self dismissViewControllerAnimated:YES completion:nil];
Am I using delegates correctly for what i want, or should i be using a different process?
Code for option 1 (A->B, B<-A):
A -> B
scorer_turn *st = (scorer_turn *) segue.destinationViewController;
st.st_delegate=self;
st.league = _match.league;
st.match = _match;
st.leg = _leg;
st.set = _set;
B -> A
-(void)closeView{
[_st_delegate scorer_turn:self didFinish:YES];
}
-(void)scorer_turn:(scorer_turn *)controller didFinish:(BOOL)finish{
[self dismissViewControllerAnimated:YES completion:nil];
}
Code for option 2 (A->B, B->C, C->B->A):
as above plus:
B -> C
matchSummaryViewController *ms = (matchSummaryViewController *) segue.destinationViewController;
ms.match = _match;
ms.oneScreen = NO;
ms.delegate = self;
[[segue destinationViewController] setManagedObjectContext:self.managedObjectContext];
C -> B, B -> A
in C:
[_delegate matchSummaryViewController:self didFinish:YES];
in B:
[self dismissViewControllerAnimated:YES completion:nil];
[_st_delegate scorer_turn:self didFinish:YES];
in A (this is where the error occurs):
-(void)scorer_turn:(scorer_turn *)controller didFinish:(BOOL)finish{
[self dismissViewControllerAnimated:YES completion:nil];
}
If ViewController B is a modalViewController, and ViewController C is pushed onto the same modalViewController, then calling
[self dismissViewControllerAnimated:YES completion:nil];
should dismiss the entire modal view - as in, it'll dismiss C and skip B all-together (B wont even appear), which would cause problems if B tries to also call dismissViewControllerAnimated:completion: since there is no more modal view to dismiss.
Now, if you have some other set-up, such as B being a modal which, when pushing C, it actually dismisses itself and launches a new modal view (this would happen if you always use the presentViewController:animated:completion function), then you have other design problems - you shouldn't be swapping modal views like that, instead use
[self.navigationController pushViewController:C animated:YES]
to show the view and
[self.navigationController popViewControllerAnimated:YES]
to dismiss View C and return to View B.
This is assuming of course that you're using a navigationController to manage your views (which you typically should be doing).
If on the other hand you aren't using modal views at all, then dismissViewControllerAnimated:completion: isn't what you want to use at all.