So, I have a tabbarcontroller, and I pass a notification to dismissModalViewController when a particular tabBarItem is touched.
It is working well and the modal View Controller is dismissed. But I want to change it in a particular way, and it does not work as I expect it to...
I have the observer initialized before the notification is posted. These are the tabBarItems -
NSArray *viewControllerss = [[NSArray alloc] initWithObjects: myProfileDataViewController,
sampleViewController,reminderInfoViewController, nil];
[self.tabBarContr setViewControllers:viewControllerss animated:YES];
self.tabBarContr.selectedIndex = 2;
I send a notification on the viewWillAppear of sampleViewController and when I choose that tabBarIcon, it dismisses the TabBarController.
BUT I want the sampleViewController to be on the left most of the UITabBar.
And so I add it like
NSArray *viewControllerss = [[NSArray alloc] initWithObjects: sampleViewController,
myProfileDataViewController, reminderInfoViewController, nil];
THIS DOES NOT DISMISS TAB BAR CONTROLLER.
Note: Please see the order in which NSArray is initialized.
The notification is posted in the viewWillAppear ofsampleViewController` and observer in the respective view controller which presents the modal view controller
Could you put a NSLog right before you post the notification?
See if you get any output when the app loads.
EDIT: Adding onto the answer based on your response
In your sampleViewController could you try this:
Make it conform to the UITabBarControllerDelegate. Your sampleViewController class interface should be something like this:
#interface SampleViewController : UIViewController <UITabBarControllerDelegate>
Then in the .m of your sampleViewController, in the viewDidLoad, set the delegate to be the sampleViewController (self in this case)
-(void) viewDidLoad
{
[super viewDidLoad];
// Assuming you have a reference to your tabBarController somewhere
[self setDelegate:self]; // try this line or the line below
// [[self tabBarController] setDelegate:self];
// The rest of your drawing code here
}
Now implement the delegate method somewhere inside the sampleViewController .m file.
-(void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
{
// I've included this to see if this method actually gets called or not.
NSLog(#"Dismissing modal view controller");
// check to make sure sampleViewController tab was pressed by checking
// the class type of the viewController parameter being passed in
if ([viewController isKindOfClass:[SampleViewController class]]
{
// I assume you have a pointer reference to that modal view controller
// you want to dismiss
[self dismissModalViewController:theUnwantedViewController animated:YES];
}
}
See if that works.
Related
Background: I would like to dismiss a modalView that I have presented earlier and right away present the same viewController that I just dismissed with new information.
Problem: I have not been very successful in doing so without an explicit pointer to the parent ViewController that presented the first ViewController modally. I am trying to write this class that works without messing around with the previous viewController's code.
Possible lead: There are couple of things I have been experimenting with:
1.) Trying to get access to the parent ViewController, which at this time I don't know how to.
2.) Once access to the parent is gained, I can simply apply the following code:
UIViewController* toPresentViewController = [[UIViewController alloc] init];
[self dismissViewControllerAnimated:YES completion:^{
[parentViewControllerAccessor presentModalViewController:toPresentViewController animated:YES];
}];
In theory this should work given the access to parent viewController. I am open to other ways of doing this.
Assumption: You do not have permission to change any code in the parent ViewController.
Your code looks like it should work. If you are using iOS 5 there is a UIViewController property called presentingViewController.
#property(nonatomic, readonly) UIViewController *presentingViewController;
So you can use this property to get the view controller that presented your modal controller.
Note: In iOS 4 parentViewController would be set to the presenting controller, so if you are supporting both iOS 4 and 5 you will have to check the OS version first to decide which property to access. In iOS 5 Apple have fixed this so that parentViewController is now exclusively used for the parent of contained view controllers (see the section on Implementing a Container View Controller in the UIViewController documentation).
Edit: Regarding accessing self.presentingViewController from within the block: By the time the block is called (after the modal view controller is dismissed) the presentingViewController property may get set to nil. Remember that self.presentingViewController inside the block gives the value of the property when the block is executed, not when it was created. To protect against this do the following:
UIViewController* toPresentViewController = [[UIViewController alloc] init];
UIViewController* presentingViewController = self.presentingViewController;
[self dismissViewControllerAnimated:YES completion:^
{
[presentingViewController presentModalViewController:toPresentViewController animated:YES];
}];
This is necessary not because self is gone/dismissed (it is safely retained by the block), but because it is no longer presented, therefore its presentingViewController is now nil. It is not necessary to store the presentingViewController anywhere else, the local variable is fine because it will be retained by the block.
You could accomplish this using notifications.
For example, fire this notification from outside the modal view when you want it to be dismissed:
[[NSNotificationCenter defaultCenter] postNotificationName:#"dismissModalView"
object:nil
userInfo:nil];
And then handle that notification inside your modal view:
- (void)viewDidLoad {
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(dismissMe:)
name:#"dismissModalView"
object:nil];
}
- (void)dismissMe:(NSNotification)notification {
// dismiss it here.
}
the solution for ios5:
-(void)didDismissModalView:(id)sender {
// Dismiss the modal view controller
int sold=0;
if(sold==0){
//Cash_sold.delegate = self;
// Cash_sold.user_amount.text=[NSString stringWithFormat:#"%d",somme];
Cash_sold = [[CashSoldview alloc] initWithNibName:#"CashSoldview" bundle:nil];
CGRect fram1 = CGRectMake(200,20,400,400);
Cash_sold.view.superview.frame = fram1;
Cash_sold.view.frame=fram1;
Cash_sold.modalTransitionStyle= UIModalTransitionStyleCoverVertical;
Cash_sold.modalPresentationStyle=UIModalPresentationFormSheet;
UIViewController* presentingViewController = self.parentViewController;
[self dismissViewControllerAnimated:YES completion:^
{
[presentingViewController presentModalViewController:Cash_sold animated:YES];
}];
}
}
Try the following code:
[self dismissViewControllerAnimated:NO
completion:^{
// instantiate and initialize the new controller
MyViewController *newViewController = [[MyViewController alloc] init];
[[self presentingViewController] presentViewController:newViewController
animated:NO
completion:nil];
}];
I am having issues with the back button not showing up on the SettingsViewController. The navigation bar does show up when the view is pushed, but no back button.
I am creating this inside a view controller, which is not a navigation controller. Any ideas or suggestions on what is actually going on here.
- (void)viewDidLoad
{
self.title = #"Settings";
}
- (IBAction)showSettingsModal:(id)sender
{
SettingsViewController *settingsViewController = [[SettingsViewController alloc] initWithNibName:#"SettingsViewController" bundle:nil];
UINavigationController *navController = [[[UINavigationController alloc] initWithRootViewController:settingsViewController] autorelease];
[self presentModalViewController:navController animated:YES];
[settingsViewController release];
}
You are creating a new navigation stack. You will need to add your own Back button and set the action of that to a delegate method on the calling VC to dismiss it.
UPDATE:
There seems to be lots of confusion about where and how to dismiss ModalViewControllers. The wrong thing to do in most cases is to call the Dismiss method from the Modal VC itself if you are wanting the parent to act on that dismissal. Instead, use delegation. Here is a simple example:
ModalViewController.h:
#protocol ModalViewControllerDelegate
-(void)dismissMyModalVC;
#end
#interface ModalViewController : UIViewController {
id < ModalViewControllerDelegate > delegate;
}
#property (nonatomic, retain) id < ModalViewControllerDelegate > delegate;
// The rest of your class properties, methods here
ModalViewController.m
#synthesize delegate;
...
// Put in the Method you will be calling from that Back button you created
[delegate dismissMyModalVC];
CallingViewController.h:
#import "ModalViewController.h"
#interface CallingViewController : UIViewController
<ModalViewControllerDelegate>
// Rest of class here
CallingViewController.m:
ModalViewController *mvc = [[ModalViewController alloc] initWithNibName:#"ModalViewController" bundle:nil];
mvc.delegate = self
[self presentModalViewController:mvc animated:YES];
...
// The ModalViewController delegate method
-(void)dismissMyModalVC {
// Dismiss the ModalViewController that we instantiated earlier
[self dismissModalViewControllerAnimated:YES];
That way the VC gets dismissed properly from the controller that instantiated it. That delegate method can be modified to pass along objects as well (like when you are finished logging a user in, etc)
SettingsViewController does not have a back button because it is at the bottom of stack. If you want a button to dismiss the modal dialog, you will have to add it yourself.
you can try this
UIBarButtonItem * backButton = [[UIBarButtonItem alloc]initWithTitle:#"Back"style:UIBarButtonItemStylePlain target:self.navigationItem.backBarButtonItem action:#selector(dismissModalViewControllerAnimated:)];
You are presenting your new controller as modal view controller. Modal controller presents its topmost. You should:
[self.navigationController pushViewController:navController animated:YES];
to push view controller onto the stack, and then you will see Back button.
Read Apple documenation on presenting view controllers:
https://developer.apple.com/library/ios/#featuredarticles/ViewControllerPGforiPhoneOS/ModalViewControllers/ModalViewControllers.html
EDIT Didn't see that the calling view controller is not part of the navigation controller. In that case, you will have to create back button manually, and set it as a left bar navigation item.
I have a mainViewController. I call [self pushModalViewController:someViewController] which makes someViewController the active view.
Now I want to call a function in mainViewController as someViewController disappears with [self dismissModalViewController].
viewDidAppear does not get called probably because the view was already there, just beneath the modal view. How does one go about calling a function in the mainViewController once the modalView dismisses itself?
Thanks a lot!
This answer was rewritten/expanded to explain the 3 most important approaches (#galambalazs)
1. Blocks
The simplest approach is using a callback block. This is good if you only have one listener (the parent view controller) interested in the dismissal. You may even pass some data with the event.
In MainViewController.m
SecondViewController* svc = [[SecondViewController alloc] init];
svc.didDismiss = ^(NSString *data) {
// this method gets called in MainVC when your SecondVC is dismissed
NSLog(#"Dismissed SecondViewController");
};
[self presentViewController:svc animated:YES completion:nil];
In SecondViewController.h
#interface MainViewController : UIViewController
#property (nonatomic, copy) void (^didDismiss)(NSString *data);
// ... other properties
#end
In SecondViewController.m
- (IBAction)close:(id)sender
{
[self dismissViewControllerAnimated:YES completion:nil];
if (self.didDismiss)
self.didDismiss(#"some extra data");
}
2. Delegation
Delegation is the recommended pattern by Apple:
Dismissing a Presented View Controller
If the presented view controller must return data to the presenting view controller, use the delegation design pattern to facilitate the transfer. Delegation makes it easier to reuse view controllers in different parts of your app. With delegation, the presented view controller stores a reference to a delegate object that implements methods from a formal protocol. As it gathers results, the presented view controller calls those methods on its delegate. In a typical implementation, the presenting view controller makes itself the delegate of its presented view controller.
MainViewController
In MainViewController.h
#interface MainViewController : UIViewController <SecondViewControllerDelegate>
- (void)didDismissViewController:(UIViewController*)vc;
// ... properties
#end
Somewhere in MainViewController.m (presenting)
SecondViewController* svc = [[SecondViewController alloc] init];
svc.delegate = self;
[self presentViewController:svc animated:YES completion:nil];
Somewhere else in MainViewController.m (being told about the dismissal)
- (void)didDismissViewController:(UIViewController*)vc
{
// this method gets called in MainVC when your SecondVC is dismissed
NSLog(#"Dismissed SecondViewController");
}
SecondViewController
In SecondViewController.h
#protocol SecondViewControllerDelegate <NSObject>
- (void)didDismissViewController:(UIViewController*)vc;
#end
#interface SecondViewController : UIViewController
#property (nonatomic, weak) id<SecondViewControllerDelegate> delegate;
// ... other properties
#end
Somewhere in SecondViewController.m
[self.delegate myActionFromViewController:self];
[self dismissViewControllerAnimated:YES completion:nil];
(note: the protocol with didDismissViewController: method could be reused throughout your app)
3. Notifications
Another solution is sending an NSNotification. This is a valid approach as well, it might be easier than delegation in case you only want to notify about the dismissal without passing much data. But it's main use case is when you want multiple listeners for the dismissal event (other than just the parent view controller).
But make sure to always remove yourself from NSNotificationCentre after you are done! Otherwise you risk of crashing by being called for notifications even after you are deallocated. [editor's note]
In MainViewController.m
- (IBAction)showSecondViewController:(id)sender
{
SecondViewController *secondVC = [[SecondViewController alloc] init];
[self presentViewController:secondVC animated:YES completion:nil];
// Set self to listen for the message "SecondViewControllerDismissed"
// and run a method when this message is detected
[[NSNotificationCenter defaultCenter]
addObserver:self
selector:#selector(didDismissSecondViewController)
name:#"SecondViewControllerDismissed"
object:nil];
}
- (void)dealloc
{
// simply unsubscribe from *all* notifications upon being deallocated
[[NSNotificationCenter defaultCenter] removeObserver:self];
}
- (void)didDismissSecondViewController
{
// this method gets called in MainVC when your SecondVC is dismissed
NSLog(#"Dismissed SecondViewController");
}
In SecondViewController.m
- (IBAction)close:(id)sender
{
[self dismissViewControllerAnimated:YES completion:nil];
// This sends a message through the NSNotificationCenter
// to any listeners for "SecondViewControllerDismissed"
[[NSNotificationCenter defaultCenter]
postNotificationName:#"SecondViewControllerDismissed"
object:nil userInfo:nil];
}
Hope this helps!
Using exit (unwind) segue
When you're using storyboards and segues you can use a very handy approach with minimal code to dismiss a modal view controller and inform the underlying view controller that the modal view controller has been closed.
Using exit (unwind) segues you gain 3 advantages:
you don't need to write any code to dismiss the modal view controller and
you can have iOS call a callback method inside the underlying view controller that has presented the model view controller.
you use the very same semantics that you already know from implementing prepareForSegue:
Implement it with only 2 steps
Create an action method in the Parent view controller that presents another (modal) view controller:
Swift
#IBAction func unwindFromSegue(segue: UIStoryboardSegue) {
print("Unwind from segue", segue.identifier)
}
Objective-C
- (IBAction)unwindFromSegue:(UIStoryboardSegue *)segue {
NSLog(#"Unwind from segue %s", segue.identifier);
}
In the storyboard, On child view controller right click the exit segue (aka unwind segue, it's the last of the icons at the top of your view controller), drag & drop unwindFromSegue: to your button and select action.
You're done! Now the modal view controller closes when you click the dismiss button and unwindFromSegue: informs your underlying view controller(Parent) that the modal view controller(Child) has closed.
Here's a callback solution which takes less modifications to your modal and parent:
In the Model's .h add:
#property (nonatomic, copy) void (^dismissed)();
In the Model's .m put this in the completion when you dismiss the modal:
[self dismissViewControllerAnimated:YES completion:^{
if(self.dismissed)
self.dismissed();
}];
In the parent view controller when you instantiate your modal set the dismissed callback:
Modal = //Init your modal
[Modal setDismissed:^{
//do stuff you wanted when it's dimissed
}];
[self presentViewController:Modal animated:YES completion:nil];
I have a button inside the content of a UIPopoverController. This button runs a method called myAction.
MyAction has the form
- (void) myAction:(id)sender
so, myAction receives the id of the caller button.
Now, inside this method I would like to dismiss the UIPopoverController, but the only thing I have is the ID of the caller button. Remember that the button is inside the UIPopoverController.
Is there a way to discover the ID of the UIPopoverController, given the button ID I already have?
thanks.
Unfortunately no. At least, not within the standard practices. You might be able to travel up the responder stack to find it, but it's a hack, it's buggy, and it's really, really messy.
If you want to dismiss a popover by pushing a button, some place relevant should keep a reference to the popover. Usually that would be the owner of the popover (not the controller showed within the popover). When the button is pressed, it can send a message to the owner controller, which can then dismiss the popover.
You might be tempted to have the controller displayed inside of the popover be the owner of its own popover, but coding this way is brittle, can get messy (again), and may result in retain loops so that neither ever gets released.
You can access the presenting popoverController by accessing "popoverController" with KVC.
[[self valueForKey:#"popoverController"] dismissPopoverAnimated:YES]
I have this working, and I do not think it is a hack. I have a standard split view iPad app. I then added a method on my detail controller (the owner of the pop over) to handle the dismissal.
On the standard split view architechture, both the root and detail view controllers are available via the app delegate. So I bound a button click inside the pop over to call a method which gets the app delegate. From there I call the method on the detail controller to dismiss the pop over.
This is the code for the method on the View Controller that is displayed inside the popover:
- (void) exitView: (id)sender {
MyAppDelegate *appDelegate = (MyAppDelegate *)[[UIApplication sharedApplication] delegate];
[appDelegate.detailViewController exitDrill];
}
Then the simple method to dismiss on the Detail View Controller:
- (void) exitDrill {
if(dtController != nil){
[dtController dismissPopoverAnimated: YES];
[dtController release];
}
}
I like the ability to do this because it give me a way to show a user how they can exit a pop over. This may not be necessary in future versions of the app; for right now, while this paradigm is still new to the platform, I prefer to let the users gexit a display in a couple fo different ways to make sure I minimize frustration.
As Ed Marty already wrote
If you want to dismiss a popover by pushing a button, some place relevant should keep a reference to the popover
This is very true; however, when showing a UIPopoverController, the class opening the popovercontroller keeps this resource already. So, what you could do is to use this class as the delegate class for your Popover Controller.
To do so, you could do the following, which I use in my code.
In the class opening the popover, this is my code:
- (void)showInformationForView:(Booking*)booking frame:(CGRect)rect
{
BookingDetailsViewController *bookingView = [[BookingDetailsViewController alloc] initWithStyle:UITableViewStyleGrouped booking:booking];
[bookingView setDelegate:self];
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:bookingView];
self.popController = [[UIPopoverController alloc] initWithContentViewController:navController];
[self.popController setDelegate:self];
[self.popController setPopoverContentSize:CGSizeMake(320, 320)];
rect.size.width = 0;
[self.popController presentPopoverFromRect:rect inView:self.view permittedArrowDirections:UIPopoverArrowDirectionLeft animated:YES];
}
- (void)dismissPopoverAnimated:(BOOL)animated
{
[self.popController dismissPopoverAnimated:animated];
}
So what I am doing here is creating a UINavigationController and setting a BookingDetailsViewController as its rootViewController. Then I am also adding the current class as delegate to this BookingDetailsViewController.
The second thing I added is a dismissal method called dismissPopoverAnimated:animated.
In my BookingDetailsViewController.h I added the following code:
[...]
#property (nonatomic, strong) id delegate;
[...]
And in my BookingDetailsViewController.m I added this code:
[...]
#synthesize delegate = _delegate;
- (void)viewDidLoad
{
UIBarButtonItem *closeButton = [[UIBarButtonItem alloc] initWithTitle:#"Close" style:UIBarButtonItemStylePlain target:self action:#selector(closeView)];
[self.navigationItem setRightBarButtonItem:closeButton];
[super viewDidLoad];
}
- (void)closeView
{
if ([self.delegate respondsToSelector:#selector(dismissPopoverAnimated:)]) {
[self.delegate dismissPopoverAnimated:YES];
}
else {
NSLog(#"Cannot close the view, nu such dismiss method");
}
}
[...]
What happens is that when the "Close" button in the UINavigationController is pressed, the method closeView is called. This method check if the delegate responds to dismissPopoverAnimated:animated and if so, it calls it. If it does not respond to this method it will show a log message and do nothing more (so it wont crash).
I have written my code using ARC, hence there is no memory management.
I hope this helped you.
I'd like to use a modal UITableView at startup to ask users for password, etc. if they are not already configured. However, the command to call the uitableview doesn't seem to work inside viewDidLoad.
startup code:
- (void)viewDidLoad {
rootViewController = [[SettingsController alloc]
initWithStyle:UITableViewStyleGrouped];
navigationController = [[UINavigationController alloc]
initWithRootViewController:rootViewController];
// place where code doesn't work
//[self presentModalViewController:navigationController animated:YES];
}
However, the same code works fine when called later by a button:
- (IBAction)settingsPressed:(id)sender{
[self presentModalViewController:navigationController animated:YES];
}
Related question: how do I sense (at the upper level) when the UITableView has used the command to quit?
[self.parentViewController dismissModalViewControllerAnimated:YES];
You can place the presentModalViewController:animated: call elsewhere in code - it should work in the viewWillAppear method of the view controller, or in the applicationDidFinishLaunching method in the app delegate (this is where I place my on-launch modal controllers).
As for knowing when the view controller disappears, you can define a method on the parent view controller and override the implementation of dismissModalViewControllerAnimated on the child controller to call the method. Something like this:
// Parent view controller, of class ParentController
- (void)modalViewControllerWasDismissed {
NSLog(#"dismissed!");
}
// Modal (child) view controller
- (void)dismissModalViewControllerAnimated:(BOOL)animated {
ParentController *parent = (ParentController *)(self.parentViewController);
[parent modalViewControllerWasDismissed];
[super dismissModalViewControllerAnimated:animated];
}
I had quite the same problem. I know the topic is old but maybe my solution could help someone else...
You just have to move your modal definition in a method:
// ModalViewController initialization
- (void) presentStartUpModal
{
ModalStartupViewController *startUpModal = [[ModalStartupViewController alloc] initWithNibName:#"StartUpModalView" bundle:nil];
startUpModal.delegate = self;
[self presentModalViewController:startUpModal animated:YES];
[startUpModal release];
}
Next, in viewDidLoad, call your modal definition method in a performSelector:withObject:afterDelay: with 0 as delay value. Like this:
- (void)viewDidLoad
{
[super viewDidLoad];
//[self presentStartUpModal]; // <== This line don't seems to work but the next one is fine.
[self performSelector:#selector(presentStartUpModal) withObject:nil afterDelay:0.0];
}
I still don't understand why the 'standard' way doesn't work.
If you are going to do it like that then you are going to have to declare your own protocol to be able to tell when the UITableView dismissed the parentViewController, so you declare a protocol that has a method like
-(void)MyTableViewDidDismiss
then in your parent class you can implement this protocol and after you dismissModalView in tableView you can call MyTableViewDidDismiss on the delegate (whihc is the parent view controller).