UINavigationItem craziness from pushing view controllers with no animation? - ios

I am pushing a viewController onto the UINavigationController with animation, and the controller being pushed on is basically doing something like:
--- app delegate:
[((UINavigationController *)window.rootViewController) pushViewController:initialController animated:YES];
--- initial controller:
- (void)viewDidLoad {
[super viewDidLoad];
if (self.shouldSkipThisController) {
SomeOtherViewController *someOther = [[SomeOtherViewController alloc] init];
[self.navigationController pushViewController:someOther animated:NO];
}
}
This is causing some CRAZY behavior which I don't understand at all. Basically, it seems like the navigation items set on SomeOtherViewController are being covered up by some strange other button that has the name of the title in a back button. It looks like although SomeOtherViewController is setting it's own left and right navigation items, they are covered up by the "default" back button--- and then if I tap on that back button, then just the navigation bar at the top animates-- and THEN SomeOtherViewController's navigation items are then there.
The only thing I could find that sort of worked was to either 1) not animate the push of the initial view controller in the app delegate, or 2) move the shouldSkipThisController condition into viewDidAppear: method.
However, neither of those options are ideal... Any help could be greatly appreciated.

Related

Navigation bar shows wrong navigation item in iOS 9.2

A UINavigationController's navigationBar will initially show the correct UINavigationItem, but then will revert to the previous UINavigationItem every time a UIViewController is pushed onto the stack.
Steps to Reproduce:
Push a UIViewController onto a UINavigationController stack
Set navigationBarHidden = YES on the navigation controller
Push another view controller onto the navigation stack.
Begin an interactive pop transition and then cancel it.
Pop back to the previous view controller
Set navigationBarHidden = NO on the navigation controller
Attempt to push a view controller onto the stack
Looks like -[UINavigationBar _cancelInteractiveTransition] is getting called, even on push transitions after getting into this state? I can set a breakpoint on that symbol, and the navigation bar shows the correct navigation item before it and the wrong navigation item afterwards.
But what I want is that the navigation controller's navigation bar should display the current topViewController's navigation item.
#interface UINavigationController (Private)
- (void)_cancelInteractiveTransition:(float)arg1 transitionContext:(id)arg2;
#end
- (void)_cancelInteractiveTransition:(float)arg1 transitionContext:(id)arg2
{
BOOL hidden = self.isNavigationBarHidden;
if (hidden) {
[self setNavigationBarHidden:NO animated:YES];
}
[super _cancelInteractiveTransition:arg1 transitionContext:arg2];
if (hidden) {
[self setNavigationBarHidden:hidden animated:YES];
}
}
I recently ran into this issue on iOS10 and I'm sure it was there on iOS9, assuming we still supported it. It turned out that the issue was that at the start of the interactive transition we were setting navigationController.navigationBarHidden=NO and then when it was cancelled forgetting to set it back to navigationController.navigationBarHidden=YES. It seems like the navigation bar doesn't like to be unhidden twice in a row. I would imagine that its the same for setting it to hidden twice in a row as well. The good news is that this was not an issue with iOS11.

Wired black space under screen when pop to previous view controller using UINavigationController

I am using UINavigationController to direct some view controllers.In some view controller, I don't want to use UINavigationBar, but in some others i may use. Now I am try to pop one view controller using UINavigationBar to its previous one which hide UINavigationBar. But when poped, there is one wired black space under screen. After you rotate the screen, the space will disappear.
the normal view controller A should be like this:
when press the text button, a view controller B will be pushed, which is as followings:
when click back button on the navigation bar. A will come out.but there is a black space at the bottom.
If rotate the screen, the space will disappear. And also in A's - (void)viewWillAppear:(BOOL)animated method i hide the navigationbar and let the screen autorotate.
- (void)viewWillAppear:(BOOL)animated
{
[self.navigationController setNavigationBarHidden:YES animated:animated];
[super viewWillAppear:animated];
[self willAnimateRotationToInterfaceOrientation:[UIApplication sharedApplication].statusBarOrientation duration:0];
}
whats wrong with this situation? Any help will be appreciated.
I add setNavigationBarHidden: method in the back button action method. it works. If i add this method in viewWillDisappear: method or others, it seems it doesn't work. The navigation bar will have effect on next appear view controller. which means, there will be a black space in the next view controller in the navigation stack.
Finally, i add a action method for the back button and setNavigationBarHidden:YES in the method, which is as follows:
- (void)backBtnClicked:(id)sender
{
[self.navigationController popViewControllerAnimated:NO];
[self.navigationController setNavigationBarHidden:YES];
}

I have view controllers in a navigation controller hierarchy, but only want the navigation bar on the first view controller - how do I do this?

I have a main view controller that lists a bunch of items, and when they tap on one of the items it segues them to the next view. However, in the next view, I don't want the navigation bar to be there, I only want it in the first view (I'm using a UIToolBar for the navigation bar, kind of like in iBooks).
How exactly do I go about achieving this? If I remove the main view controller from the navigation controller completely (unembedding, effectively) I can implement the nav bars selectively, but this solution doesn't allow segues, so it's no good.
My other solution was to call self.navigationController.navigationBarHidden = YES; in viewDidAppear for the second view, but with this, the UIToolBar that I added in my storyboard is pushed under the navigation bar that hasn't been hidden yet, and then when it does get hidden, it disappears and the UIToolBar "falls down", which is a pretty gross effect to the user.
What would be the best way to go about getting this effect?
The best way to do that is the following. In you viewWillAppear: in the first (rootViewController) of your UINavigationController, you set:
-(void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[self.navigationController setNavigationBarHidden:NO animated:animated];
}
and then in you viewWillDisappear, you the the opposite:
-(void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
[self.navigationController setNavigationBarHidden:YES animated:animated];
}
This way should work without nothing 'ugly' happening to the user.

iOS: Pushing a view controller with animation only works once

I am creating an iPhone client for one of my apps that has an API. I am using the GTMOAuth2 library for authentication. The library takes care of opening a web view for me with the correct url. However I have to push the view controller myself. Let me show you some code to make things more clear:
- (void)signInWithCatapult
{
[self signOut];
GTMOAuth2ViewControllerTouch *viewController;
viewController = [[GTMOAuth2ViewControllerTouch alloc] initWithAuthentication:[_account catapultAuthenticaiton]
authorizationURL:[NSURL URLWithString:kCatapultAuthURL]
keychainItemName:kCatapultKeychainItemName
delegate:self
finishedSelector:#selector(viewController:finishedWithAuth:error:)];
[self.navigationController pushViewController:viewController animated:YES];
}
I have a "plus"/"add" button that I add to the view dynamically and that points to that method:
self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:#selector(signInWithCatapult)];
When I press the "add" button, what is supposed to happen is to open the web view with an animation, and then add an account to the accounts instance variable which populates the table view. This works fine if I add one account, but as soon as I try to add a second account, the screen goes black and two errors appear in the console:
nested pop animation can result in corrupted navigation bar
Finishing up a navigation transition in an unexpected state. Navigation Bar subview tree might get corrupted.
The only way that I found to avoid this problem was to disable animations when pushing the view controller.
What am I doing wrong please?
Typical situations
You push or pop controllers inside viewWillAppear: or similar methods.
You override viewWillAppear: (or similar methods) but you are not calling [super viewWillAppear:].
You are starting two animations at the same time, e.g. running an animated pop and then immediately running an animated push. The animations then collide. In this case, using [UINavigationController setViewControllers:animated:] must be used.
Have you tried the following for dismissing once you're in?
[self dismissViewControllerAnimated:YES completion:nil];
I got the nested pop animation can result in corrupted navigation bar message when I was trying to pop a view controller before it had appeared. Override viewDidAppear to set a flag in your UIViewController subclass indicating that the view has appeared (remember to call [super viewDidAppear] as well). Test that flag before you pop the controller. If the view hasn't appeared yet, you may want to set another flag indicating that you need to immediately pop the view controller, from within viewDidAppear, as soon as it has appeared. Like so:
#interface MyViewController : UIViewController {
bool didAppear, needToPop;
}
...and in the #implementation...
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
didAppear = YES;
if (needToPop)
[self.navigationController popViewControllerAnimated:YES];
}
- (void)myCrucialBackgroundTask {
// this task was presumably initiated when view was created or loaded....
...
if (myTaskFailed) { // o noes!
if (didAppear)
[self.navigationController popViewControllerAnimated:YES];
else
needToPop = YES;
}
}
The duplicated popViewControllerAnimated call is a bit ugly, but the only way I could get this to work in my currently-tired state.

Black view instead of table

I got a tabbar application.
There is only 2 tabs in the tabbar. First tab is a NavigationController, second is a TableViewController. Second works perfect, but the the first doesn't.
When i start application, i saw black window. And there is not title on the NavigationBar.
self.navigationBar.topItem.title = #"Routes";
What's the problem? Thnx.
Well, you haven't pushed a view controller to your navigation controller yet. A navigation controller is just a container for another UIViewController.
Do something like this:
- (void)viewDidLoad {
[super viewDidLoad]
// Initialize an UIViewController here ...
[self pushViewController:myRootViewController animated:NO];
}

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