I have a photo selection flow that that goes as such:
VC1 push to VC2, present modal, dismiss modal, push VC3.
Upon dismissing the modal view however, self.navigationController is null
Modal View:
[self dismissViewControllerAnimated:YES completion:^{
FBGalleryVC *vc = [[FBGalleryVC alloc] init];
[vc showVC3];
}];
Triggers VC2:
- (void)showVC3 {
NSLog(#"NavController=%#",self.navigationController);
VC3 *vc3 = [self.storyboard instantiateViewControllerWithIdentifier:#"VC3"];
[self.navigationController pushViewController:vc3 animated:YES];
}
It's unclear to me why the navigationController is getting 'unset' or returning as null.
Related
This issue only occurs on iPhone 5, regardless of iOS version.
I present the secondViewController from the firstViewController it
is presented this time.
I then dismiss the secondViewController.
I attempt to present the secondViewController again from the
firstViewController, this time it isn't presented but the UI is blocked,
From logging the process I can see that viewWillAppear method is called the first time but not the second time.
FirstViewController
- (void)presentView {
SecondViewController *secondViewController = [[SecondViewController alloc] init];
secondViewController.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
[self presentViewController:secondViewController animated:YES completion:nil];
}
SecondViewController
- (void)dismissView {
[self.presentingViewController dismissViewControllerAnimated:YES completion:nil];
}
Currently my scenario like this ,
View Controller(VC1) --> Push Segue --> View Controller(VC2)
| ^
| Model Segue |
| | Push Segue
|-----> View Controller(VC3) ------|
Now in VC3 when i push in to VC2 i want to dismiss VC3 view Controller and
on after VC2 back button it should be VC1's back view controller i want to pop VC3
What i want is i want to remove VC3 when i push the VC2 from VC3 when we back then it VC1 should appear
Check Example
I have done like this can anyone help me out
View Controller (VC3) :
- (void)callWebservice {
[self dismissViewControllerAnimated:YES completion:^{
[self performSegueWithIdentifier:#"showVC2" sender:self];
}];
}
Thanks in advance
I think you can implement in that way:
when you at screen 3 you want push screen 2. You will dismiss screen 3 and call a delegate back screen 1.
And from screen1 you will push view to screen2.
You can see my demo for my idea: Demo Pushview Swift
DemoPushViewObj
I think you are looking for https://stackoverflow.com/a/21415225/1320305 if you are using segue, to do this manually try following:
you can try this
// locally store the navigation controller since
// self.navigationController will be nil once we are popped
UINavigationController *navController = self.navigationController;
// retain ourselves so that the controller will still exist once it's popped off
[[self retain] autorelease];
// Pop this controller and replace with another
[navController popViewControllerAnimated:NO];//not to see pop
[navController pushViewController:aViewController animated:YES];
//to see push or u can change it to not to see.
OR try this
UIViewController *newVC = [[UIViewController alloc] init]; // Replace the current view controller
NSMutableArray *viewControllers = [NSMutableArray arrayWithArray:[[self navigationController] viewControllers]];
[viewControllers removeLastObject];
[viewControllers addObject:newVC];
[[self navigationController] setViewControllers:viewControllers animated:YES];
I have this navigation stack
RootVC ---> VC1 --> (presenting)-> ModalVC
and I have VC2 (not in navigation stack).
When presenting ModalVC, I want to click on button in my ModalVC to dismiss ModalVC, then push VC2 into the navigation stack after VC1 at one click. It should look like this:
RootVC ---> VC1 ---> VC2
I tried a lot of methods to make it, but pushing event fire only, when I return to my RootVC.
I tried to make it with delegates:
In ModalVC on click:
[self dismissViewControllerAnimated:YES completion:^{
if ([self.delegate respondsToSelector:#selector(dismissAndPush:)]) {
[self.delegate performSelector:#selector(dismissAndPush:) withObject:VC2];
}
}];
In VC1:
- (void)dismissAndPush:(UIViewController *)vc {
[self.navigationController pushViewController:vc animated:NO];
}
Please help to understand this behavior. Where is my mistake?
From Apple Documentation:
The presenting view controller is responsible for dismissing the view
controller it presented.
So, VC1 should be dismissing the ModalVC, try to do this
ModalVC on click:
if ([self.delegate respondsToSelector:#selector(dismissAndPush:)]) {
[self.delegate performSelector:#selector(dismissAndPush:) withObject:VC2];
}
In VC1:
- (void)dismissAndPush:(UIViewController *)vc {
[self dismissViewControllerAnimated:YES completion:^{
[self.navigationController pushViewController:vc animated:NO];
}];
}
Error has been in other. If Im right understand: some animations before dismissing presented view controller are blocking animations in navigation stack. I solved this problem with 2 ways:
1) deleteting or set right animations before dismissing
2) use setViewControllers in navigation controller (I select it)
- (void)dismissAndPush:(UIViewController *)vc {
[self dismissViewControllerAnimated:NO completion:^{
NSMutableArray *mutableControllers = [NSMutableArray arrayWithArray:self.navigationController.viewControllers];
NSArray *controllers = [mutableControllers arrayByAddingObject:vc];
[self.navigationController setViewControllers:controllers animated:NO];
}];
}
I have simple application with only one main view, which has 'Settings' button, and settings are tree-grouped, so I wand to present them in navigation controller. And I don't want navigationController in main view, because I don't want navigation bar there.
That's why I don't instantiate navigationController in application: didFinishLaunchingWithOptions:. And when I check self.navigationController in 'Settings' button handler, it returns nil.
So I wrote this: (I use ARC)
- (void)doSettings
{
NSLog(#"%#", self.navigationController); // prints nothing
SettingsViewController *settingsViewController = [SettingsViewController alloc] initWithStyle:UITableViewStyleGrouped];
UINavigationController *navigationController = [[UINavigationController alloc] init];
[self.view.window setRootViewController:navigationController];
[navigationController pushViewController:settingsViewController animated:YES];
}
This works, although it pushes settingsViewController without animation (don't know why).
Is this generally the correct way to do - to change rootViewController in the middle of running app?
And if yes - than when I'm done with Settings, I probably need to set rootViewController back to current viewController, as it was before I tapped 'Settings'?
I think you want to create a navigation controller that you will present modally; the following will do:
SettingsViewController* settingsViewController = [[SettingsViewController alloc] initWithStyle:UITableViewStyleGrouped];
UINavigationController *navigationController = [[UINavigationController alloc] init];
[navigationController pushViewController:settingsViewController animated:YES];
[self presentViewController: navigationController animated: YES completion:nil];
where self here is the view controller you want to trigger the modal view controller from.
since you present modally the navigation controller you can dismiss it within the code source of your settingsViewController by accessing its navigation controller:
[self.navigationController dismissViewControllerAnimated:YES completion: nil];
To answer your question setting the rootViewController is not the correct way. Present the new vc modally through the presentViewController method.
A better way is to build the navigation vc and present it over your main vc (not replace your main vc).
- (void)doSettings
{
NSLog(#"%#", self.navigationController); // prints nothing
SettingsViewController *settingsViewController = [SettingsViewController alloc] initWithStyle:UITableViewStyleGrouped];
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController: settingsViewController];
[self presentViewController: navigationController animated:YES completion:^{}];
}
Your main vc might realize (maybe as a delegate) that the settings flow is complete. It can then dismiss the presented navigation controller with:
- (void)dismissViewControllerAnimated:(BOOL)flag completion:(void (^)(void))completion
Alternatively, the setting flow could dismiss itself...
// somewhere in the settings vc or a vc it pushes, when we decide settings are done
self.navigationController dismissViewControllerAnimated:YES completion:^{}];
Have navigation in main view and have below line (which will hide navigation bar)
[[self navigationController] setNavigationBarHidden:YES animated:YES];
(I would say have this in viewWillAppear and viewDidLoad both, BUT in viewWillAppear is MUST).
Now in second view, to show navigation bar
[[self navigationController] setNavigationBarHidden:NO animated:YES];
Hope this will solve your problem...
In my app i present a UINavigationController modally with a UIViewController as its rootViewController. I do it in form style. I added a second UIViewController which is also in form style and i can push to it fine. However when i perform a popViewController action after the second UIViewcontroller gets popped onto the first, the whole modally presented UIViewController gets dismissed. However i don't perform any dismissing and the dismissing function doesn't get triggered by accident either.
Any ideas why it's happening?
Sincerely,
Zoli
EDIT:
That's how i'm presenting the modal viewcontrollers with a navcontroller:
if(!welcomeScreenAlreadyPresented) {
welcomeScreenViewController = [[WAWelcomeViewController alloc]init];
}
welcomeScreenNavController = [[UINavigationController alloc]initWithRootViewController:welcomeScreenViewController];
[welcomeScreenNavController setModalTransitionStyle: UIModalTransitionStyleCrossDissolve];
[welcomeScreenNavController setModalPresentationStyle:UIModalPresentationFormSheet];
[welcomeScreenNavController setNavigationBarHidden:YES animated:NO];
[self.navigationController presentViewController:welcomeScreenNavController animated:YES completion:nil];
That's how i'm navigation in WAWelcomeViewController.m
registerViewController = [[WARegisterViewController alloc]init];
[self.navigationController pushViewController:registerViewController animated:YES];
And in WARegisterViewController.m that's how i pop back
[self.navigationController popViewControllerAnimated:YES];
What you need to do is put the viewController you want to push inside another UINavigationController.
registerViewController = [[WARegisterViewController alloc]init];
UINavigationController *modalNavigationController = [[UINavigationController alloc] initWithRootViewController:registerViewController]; // autorelease if you are not using ARC
[self presentViewController:navController animated:YES completion:^{}];
You might want to add the modalNavigationController as a property to later call popViewControllerAnimated: on it.