I am having a strange problem that I can't seem to find the cause for.
When attempting to present a modal view controller on a navigation controller the navigation controller is popping all of my view controllers underneath when the modal is dismissed.
So after pushing a few view controllers and presenting a modal on the topViewController, I end up back at the rootViewController when the modal is dismissed.
Anyone had this happen to them lately, I can't seem to find the reasoning for why this is happening?
This answer is for #rshev:
It was actually a user error. Here's what was happening: I had a view controller with a manually added navigationController on top of it (as a subview/child VC). The nav controller then had 3 VCs in its stack. The third (and visible) VC was presenting an image picker controller. When the image picker was dismissed, I momentarily saw my third VC , then it quickly popped back to the 1st, discarding the other two VC's from memory.
So what went wrong? What I didn't realize is that viewDidAppear (and viewWillAppear) was being called on my content view controller (the one with nav controller for its subview). This content VC was actually setting its navigation controller (and adding it as a subview) on viewDidAppear, thus covering up the original nav controller.
To solve it, I just added a static boolean to determine when the first VC FIRST appears, like so:
- (void) viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
static BOOL firstAppearance = YES;
if (firstAppearance)
{
firstAppearance = NO;
UINavigationController *navController = [self.storyboard instantiateViewControllerWithIdentifier:#"NavigationController"];
[navController.view setFrame:self.view.bounds];
[self.view addSubview:navController.view];
[self addChildViewController:navController];
[navController didMoveToParentViewController:self];
}
}
Hope that helps.
Related
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'm experiencing a memory leak (the UINavigationController and its root View Controller are both being leaked) when presenting and dismissing a UINavigationController in a subview. My method of presentation of the navigation controller seems a bit non-standard, so I was hoping someone in the SO community might be able to help.
1. Presentation
The Navigation Controller is presented as follows:
-(void) presentSubNavigationControllerWithRootViewControllerIdentifier:(NSString *)rootViewControllerIdentifier inStoryboardWithName:(NSString *)storyboardName {
// grab the root view controller from a storyboard
UIStoryboard * storyboard = [UIStoryboard storyboardWithName:storyboardName bundle:nil];
UIViewController * rootViewController = [storyboard instantiateViewControllerWithIdentifier:rootViewControllerIdentifier];
// instantiate the navigation controller
UINavigationController * nc = [[UINavigationController alloc] initWithRootViewController:rootViewController];
// perform some layout configuration that should be inconsequential to memory management (right?)
[nc setNavigationBarHidden:YES];
[nc setEdgesForExtendedLayout:UIRectEdgeLeft | UIRectEdgeRight | UIRectEdgeBottom];
nc.view.frame = _navControllerParentView.bounds;
// install the navigation controller (_navControllerParentView is a persisted IBOutlet)
[_navControllerParentView addSubview:nc.view];
// strong reference for easy access
[self setSubNavigationController:nc];
}
At this point, my expectation is that the only "owner" of the navigation controller is the parent view controller (in this case, self). However, when dismissing the navigation controller as shown below, it is not deallocated (and as a result its rootViewController is also leaked, and so on down the ownership tree).
2. Dismissal
Dismissal is pretty simple, but it seems not to be sufficient for proper memory management:
-(void) dismissSubNavigationController {
// prevent an orphan view from remaining in the view hierarchy
[_subNavigationController.view removeFromSuperview];
// release our reference to the navigation controller
[self setSubNavigationController:nil];
}
Surely something else is "retaining" the navigation controller as it is not deallocated. I don't think it could possibly be the root view controller retaining it, could it?
Some research has suggested that retainCount is meaningless, but FWIW I've determined that it remains at 2 after dismissal, where I would expect it to be zero.
Is there an entirely different / better method of presenting the subNavigationController? Maybe defining the navigation controller in the storyboard would have greater benefit than simply eliminating the need for a few lines of code?
It is best practice when adding a controller's view as a subview of another controller's view, that you make that added view's controller a child view controller; that is, the controller whose view your adding it to, should implement the custom container controller api. An easy way to set this up is to use a container view in the storyboard which gives you an embedded controller automatically (you can select that controller and, in the edit menu, choose embed in Navigation controller to get the UI you're trying to make). Normally, this embedded view controller would be added right after the parent controller's view is loaded, but you can suppress that by implementing shouldPerformSegueWithIdentifier:sender:. I created a simple test app with this storyboard,
The code in ViewController to suppress the initial presentation, and the button methods to subsequently present and dismiss it is below,
#implementation ViewController
-(BOOL)shouldPerformSegueWithIdentifier:(NSString *)identifier sender:(id)sender {
if ([identifier isEqualToString:#"Embed"]) { // The embed segue in IB was given this identifier. This method is not called when calling performSegueWithIdentifier:sender: in code (as in the button method below)
return NO;
}else{
return YES;
}
}
- (IBAction)showEmbed:(UIButton *)sender {
[self performSegueWithIdentifier:#"Embed" sender:self];
}
- (IBAction)dismissEmbed:(UIButton *)sender {
[[self.childViewControllers.firstObject view] removeFromSuperview];
[self.childViewControllers.firstObject willMoveToParentViewController:nil];
[self.childViewControllers.firstObject removeFromParentViewController];
}
#end
The navigation controller and any of its child view controllers are properly deallocated when the Dismiss button is touched.
The navigationController property on a UIViewController is retain/strong, which is presumably the other strong reference.
So try popping all view controllers from the navigation controller and see if that works.
I have a storyboard in my application with a navigation controller and several views. This automatically puts a navigation bar with a back button into any views that are not the root view.
However, sometimes I navigate away from this storyboard to an individual nib. I want to navigate back to the storyboard, but not necessarily to the original root view. I currently use this method to do so:
+(void) TransitionOnStoryboard:(NSString*)storyboard to:(NSString*)identifier withViewController:(UIViewController*)viewController
{
UIStoryboard *sb = [UIStoryboard storyboardWithName:storyboard bundle:nil];
UIViewController *vc = [sb instantiateViewControllerWithIdentifier:identifier];
vc.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[viewController presentViewController:vc animated:YES completion:NULL];
}
This shows the view I want but without the navigation bar. How do I specify my navigation controller or root view, such that the app knows to put a navigation bar with a back button in?
Thanks
The answer is to leave your navigation controller underneath the view controller you add from a nib.
Present the nib as a full0-screen modal. That gets rid if your navigation bar, as desired. From that new view controller, you can push more modals, add a navigation controller, or whatever.
Note that you could do all of this and stay inside your storyboard as well.
Once you are done, dismiss the modal to reveal your navigation controller, and you are back in business with your storyboard. You can push a new view controller onto your navigation controller without animation and it should appear as the front-most VC when you pop the modal that came from a nib.
I'm sure that this isn't the ideal way to solve this problem, but it did work very nicely for me.
Essentially, I removed all the views from the view controller that had been generated since I navigated away from the storyboard, but before the current view and popped the current view. In this case, these views were of one class (CheckboxListViewController) and so could be removed quite simply as below:
+(void) navigateToMainMenu:(UINavigationController*)navigationController
{
[QuickView removeFromNavigationController:navigationController allOfViewControllerWithClass:[CheckboxListViewController class]];
[navigationController popViewControllerAnimated:YES];
}
+(void) removeFromNavigationController:(UINavigationController *)navigationController allOfViewControllerWithClass:(Class)viewControllerClass
{
NSMutableArray *keptViewControllers = [[NSMutableArray alloc]init];
for (UIViewController *viewController in navigationController.viewControllers)
if (![viewController isKindOfClass:viewControllerClass])
[keptViewControllers addObject:viewController];
navigationController.viewControllers = keptViewControllers;
}
(note- QuickView is the name of the class that contains these methods.).
Any other classes that you do not want your pop to navigate back to can be removed by calling:
[QuickView removeFromNavigationController:navigationController allOfViewControllerWithClass:[YourClassName class]];
In the navigateToMenu method.
I have a view controller (which is the root view of the main UINavigationController for my app) that is presenting another view controller hierarchy modally, by presenting a UINavigationController. After the user interacts with the root view controller in the modal NavController, a detail VC is pushed onto the modal NavController's stack. After some interaction with this detail VC, I'd like to push this detail VC back onto the original hierarchy, and dismiss the modal NavController/it's root view controller, all without the user seeing the change in this hierarchy. Right now I have something like this:
In MyViewController1 (root of the main NavController hierarchy):
UINavigationController *newModalNavController = [[UINavigationController alloc]
initWithRootViewController:someRootViewController];
[self presentViewController:newModalNavController animated:YES completion:nil];
Then in the someRootViewController above, after some interaction (e.g. a button click), I push the detail view controller onto the modal hierarchy:
[self.navigationController pushViewController:detailVC animated:YES];
Finally, in the detailVC, after some more interaction:
UINavigationController *mainNavController = /* Get main nav controller here (i.e. non-modal one) */
// Dismisses the modal view hierarchy (detailVC gets -(void)viewDidDisappear)
[self.presentingViewController dismissViewControllerAnimated:NO completion:nil];
// Repush the detailVC back onto the main hierarchy (detailVC gets -(void)viewDidAppear)
[mainNavController pushViewController:self animated:NO];
// Keyboard was on screen before interaction; make it stay on screen after pushing
// detailVC onto main nav hierarchy
[self.textView becomeFirstResponder];
This all works (clicking back on the detailVC's navigationItem after pushing it onto the mainNavController's hierarchy goes back to the original rootViewController, MyViewController1), except when the keyboard is on screen in the detail view controller as it is being switched, it gets hidden and then animates back up, instead of just staying on screen (because the view is disappearing for a second as the presentingViewController dismisses the modal nav controller, whose hierarchy the detailVC is a part of, and then reappears as it gets pushed onto the mainNavController's stack, and the textView grabs first responder again).
Is there a better way to change which navigation hierarchy the detail view controller is a part of, possibly one that doesn't involve the view disappearing, and thus the keyboard being hidden and immediately reshown?
I'm trying to use a popover as an intermediary menu between my main view and a modal view controller. I can successfully present the Modal view controller from the popover by using the following code:
UIStoryboard *storyboardiPad = [UIStoryboard storyboardWithName:#"MainStoryboard_iPad" bundle:nil];
cbwEditControlPanel *editCP = [storyboardiPad instantiateViewControllerWithIdentifier:#"EditCP"];
UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:editCP];
[nav setToolbarHidden:NO];
[nav setModalPresentationStyle:UIModalPresentationFullScreen];
[nav setModalTransitionStyle:UIModalTransitionStyleCoverVertical];
[self presentViewController:nav animated:YES completion:nil];
self.modalInPopover = NO;
The problem I'm running into is that when the EditCP modal view controller is dismissed, the main view controller never updates. I have a pagecontroller on the main view that should be updated to reflect the number of pages as set in the EditCP modal view controller, but for some reason the modal view controller being called from the popover prevents the main view controller from updating the pagecontroller. I've even tried calling the main view's "View Will Appear" method from the popover or modal view when they are dismissed, but even if the 'viewWillAppear' method is called the pageController will not update!
Any ideas what is preventing the pageController from updating? I even passed a reference to the pagecontroller to the modal view and tried to update it there, but it seems that from the time the popover is presented until it is dismissed, I cannot update the number of pages on the PageController.
Thank you!
So this is an old question but I also came across a similar problem recently when using a popover. My solution was to use an unwind segue to trigger my parent view to perform some action. In my case my parent view contains contact information and the popover contains a list of cites. All I wanted to do was to have the parent view update with the new city once the user selected it from the popover. So in my parent view I create my unwind function as follows:
In the .h:
- (IBAction)unwindToContactTVC:(UIStoryboardSegue *)unwindSegue;
In the .m:
- (IBAction)unwindToContactTVC:(UIStoryboardSegue *)unwindSegue
{
[self updateTableForOffice];
}
In the above .m file is where you would have the logic to do whatever it is you want to in the parent view. To connect this unwind segue go to the child view in the storyboard and control drag from the view icon to the exit icon. You should see a pop up with the name of your unwind segue.
Finally, give that unwind segue a name and then in the child controller in the viewWillDisappear() function call the segue as follows:
- (void)viewWillDisappear:(BOOL)animated
{
[self performSegueWithIdentifier:#"unwind-to-contact-tvc" sender:self];
}
I hope that helps. If someone has a better solution let me know.
Well, I half solved the problem. The only way to get an update function when the popover disappeared was to stop using Storyboards and programmatically present the popover, using the main view as the delegate. I then was able to update correctly inside the popoverControllerDidDismissPopover method.
However, I am still interested in finding a way to update the pageControl when the modal is dismissed, before the popover is dismissed.