-(void)backAction:(id)sender
{
SecondViewController *viewCtrl = [[SecondViewController alloc] init];
[self.presentingViewController dismissModalViewControllerAnimated:NO];
[self.presentingViewController presentModalViewController:viewCtrl animated:YES];
}
I want to dismissModalViewControllerAnimated the current controller,then present a new controller. But it only dismissModalViewControllerAnimated:NO.
why?
self.presentingViewController will be nil after you dismiss yourself in the first line. So all you have to do is get a direct reference to whatever that controller is before you do the dismissal. In the following example, the presenting view controller is of the ViewController class. You will have to use what ever class is your actual presenting view controller.
-(void)backAction:(id)sender {
ViewController *presenter = (ViewController *)self.presentingViewController;
SecondViewController *viewCtrl = [[SecondViewController alloc] init];
[presenter dismissModalViewControllerAnimated:NO];
[presenter presentModalViewController:viewCtrl animated:YES];
}
In this line, you are already dismissing the view controller
[self.presentingViewController dismissModalViewControllerAnimated:NO];
Then in the next line you are trying to preset a modal view using the view controller that was already dismissed.
[self.presentingViewController presentModalViewController:viewCtrl animated:YES];
Instead try presenting the modal view using a the parent view controller (if you have any) of both these views. You can also fire a notification to your parent view controller after dismissing the first view so that you can launch the second modal view from the parent view controller.
Maybe you can try this:
[self.presentingViewController dismissViewControllerAnimated:NO completion:^{
[self.presentingViewController presentModalViewController:viewCtrl animated:YES];
}]
Related
I have two viewcontrollers. Here is the second one:
UIViewController *modal = [[ModalViewController alloc]init];
[self presentViewController:modal animated:YES completion:nil];
Second modal window:
[self dismissViewControllerAnimated:YES completion:nil];
How do I pass parameters from a modal view controller?
If I understand you correctly, you would like to make / tell the presenting controller to dismiss the modal view controller from the modal view controller?
I gather that being the reason why you thought of passing self as "parameter" to the modal view controller, so that it could reference it and make it dismiss the ModalViewController through the use of [self dismissViewControllerAnimated:YES completion:nil]; as you mentioned?
If so, you could make use of protocol:
In your modal view controller's header file (.h), declare:
#protocol ModalViewControllerProtocol
#require
- (void)dismiss;
#end
#interface ModalViewController
In your presented controller, which is ModalViewController in your case, declare the following in .h:
#property(assign, nonatomic) id<ModalViewControllerProtocol>myDelegate;
and make your presenting controller so that it adopts to the protocol:
#interface presentingViewController <ModalViewControllerProtocol>
And:
ModalViewController *modal = [[ModalViewController alloc] init];
modal.myDelegate = self;
[self presentViewController:modal animated:YES completion:nil];
When your modal view controller is presented and you would like to tell your presenting controller to dismiss it, you could do:
[self.myDelegate dismiss];
And finally implement the dismiss method in your presenting view controller:
- (void)dismiss
{
[self dismissViewControllerAnimated:YES completion:nil];
}
One could also forget about all of the aforementioned and simply call the following in the presented view controller (which, in your case, the ModalViewController):
[self.presentingViewController dismissViewControllerAnimated:YES completion:nil];
But there are cases that self.presentingViewController is not returning the same controller that presented the modal view controller. Hence, using the protocol method would assure that we would like the same presenting view controller to dismiss the presented controller.
In a view that was created modally, pressing a button causes the modal view to be dismissed and another modal view to load.
- (void)loadLanguageSelectionView {
[self dismissViewControllerAnimated:YES completion:nil];
UIViewController *languageSelectionController = [[LanguageSelectionViewController alloc] initWithNibName:nil bundle:nil];
[languageSelectionController setModalPresentationStyle:UIModalPresentationCustom];
[languageSelectionController setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
[self presentViewController:languageSelectionController animated:YES completion:nil];
}
The following error is thrown when this code block executes:
DenkoStation[4259:73173] Warning: Attempt to present <LanguageSelectionViewController: 0x7b185430> on <ViewController: 0x79f52e50> whose view is not in the window hierarchy!
What surprises me is the fact that the code was running happily before I made some changes to my code as outlined here.
Where's the mistake?
Because you are trying to present a viewController on top of a viewController which is already dismissed and no longer in window hierarchy.
What you can try is, you can take the ParentViewController reference from current viewController and then you can present new viewController on ParentViewController Like This :
- (void)loadLanguageSelectionView {
UIViewController *parentController = self.presentingViewController;
[self dismissViewControllerAnimated:YES completion:^{
UIViewController *languageSelectionController = [[LanguageSelectionViewController alloc] initWithNibName:nil bundle:nil];
[languageSelectionController setModalPresentationStyle:UIModalPresentationCustom];
[languageSelectionController setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
[parentController presentViewController:languageSelectionController animated:YES completion:nil];
}];
}
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...
I am presenting a modal view controller on the iPad which changes the presenting view controller while presented. For example:
A view controller VC presents the modal view controller when the user selects a cell in a table view.
The user selects an item on the modal view controller and another VC instance is opened in place of the first. Importantly, the view controller instance replacing the first is of the same type.
The modal view controller cannot be dismissed or an EXC_BAD_ACCESS exception occurs.
The failing dismiss is understandable: the presenting view controller is no longer available. Basically, how would I dismiss this presented modal view controller from a different presenting view controller?
The code I already have is:
ViewController1.m
- (void)showModalViewController:(UIViewController *)viewController
{
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:viewController];
navigationController.modalPresentationStyle = UIModalPresentationFormSheet;
viewController.navigationItem.rightBarButton = [[UIBarButton alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:#selector(dismissModalViewController)];
[self presentViewController:navigationController animated:YES completion:nil];
}
- (void)dismissModalViewController
{
[self dismissViewControllerAnimated:YES completion:nil];
[self.tableView deselectRowAtIndexPath:[self.tableView indexPathForSelectedRow] animated:YES];
}
Thanks for your suggestions but I solved the issue by using delegation. The presented view controller defined a delegate to notify the presenter when an action occurred.
ChildViewControler.h:
#protocol ChildViewControllerDelegate <NSObject>
- (void) childView:(ChildViewController *)childView didSelectItem:(Item *)item;
#end
ChildViewController.m:
// in interface
#property (nonatomic, weak) id <ChildViewControllerDelegate> delegate;
// in implementation
- (void)closeView:(Item *)anItem
{
[self.delegate childView:self didSelectItem:anItem];
}
ViewController1.m:
- (void)showModalViewController:(UIViewController *)viewController
{
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:viewController];
navigationController.modalPresentationStyle = UIModalPresentationFormSheet;
viewController.navigationItem.rightBarButton = [[UIBarButton alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:#selector(dismissModalViewController)];
// Different view controller types may be passed here so check is required...
if (viewController.class == [ChildViewController class]) {
((ChildViewController *)viewController).delegate = self;
[self presentViewController:navigationController animated:YES completion:nil];
}
- (void)childView:(ChildViewController *)childView didSelectItem:(Item *)item
{
[self dismissViewControllerAnimated:YES completion:nil];
[self.tableView deselectRowAtIndexPath:[self.tableView indexPathForSelectedRow] animated:YES];
// Perform action required with 'item'
}
You can try to change
self.presentingViewController
(The view controller that presented this view controller or its farthest ancestor.)
property in your modal View Controller before dismissing.
Here is your problem:
//...
viewController.navigationItem.rightBarButton = [[UIBarButton alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:#selector(dismissModalViewController)];
//...
- (void)dismissModalViewController
{
[self dismissViewControllerAnimated:YES completion:nil];
[self.tableView deselectRowAtIndexPath:[self.tableView indexPathForSelectedRow] animated:YES];
}
You try to dismiss presenter view controller (that is currently seems to be swithced to another already) instead of presented modal view controller (in your case it UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:viewController];)
so (if presenters view controllers not the tabs of tabViewController or not stored in navigationController's stack or somewhere else) you must to store reference to it somewhere else than in presenter view controller which will be switched and could be deallocated.
As per document presentingViewController is a readonly property.
You could not modify it.
#property(nonatomic,readonly) UIViewController *presentingViewController NS_AVAILABLE_IOS(5_0);
I have not tested this code but there may be error in dismissModalViewController.
please put break point on this method the first line is perfect may your second line may cause error,may self.tableView is not accessible or self.tableView indexPathForSelectedRow may be nil.
- (void)dismissModalViewController
{
[self dismissViewControllerAnimated:YES completion:nil];
[self.tableView deselectRowAtIndexPath:[self.tableView indexPathForSelectedRow] animated:YES];
}
Thanks.
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.