I'm sure this has been asked countless times, and I've seen similar questions though the answer still eludes me.
I have an application with multiple view controllers and as a good view controller does its own task. However I find myself stuck in that I can't switch from one view controller to another. I've seen many people say "use a navigation controller" but this isn't what I want to use due to the unwanted view elements that are part and parcel to view controller.
I've done the following and have had limited success. The view controller is switched but the view does not load and I get an empty view instead:
- (IBAction)showLogin:(id)sender
{
PPLoginViewController *login = [[PPLoginViewController alloc] initWithNibName:#"PPLoginViewController" bundle:nil];
PPAppDelegate *appDelegate = [UIApplication sharedApplication].delegate;
appDelegate.window.rootViewController = login;
[self.view insertSubview:login.view atIndex:0];
}
Using UINavigationController as a rootViewController is a good tone of creating iOS application.
As i understand unwanted view elements is a navigationBar? You can just hide it manually, setting:
[self.navigationController setNavigationBarHidden:YES];
And about your case, if you want to change you current viewController(targeting iOS 6), you can just present new one:
[self presentViewController:login animated:YES completion:nil];
or add child (Here is nice example to add and remove a child):
[self addChildViewController:login];
Why to set UINavigationController as a root?
1) First of all it makes your application visible viewcontrollers to be well structured. (Especially it is needed on iPhone). You can always get the stack and pop (or move) to any viewController you want.
2) Why I make always make navigation as a root one, because it makes the application more supportable, so to it will cost not so many code changes to add some features to the app.
If you create one (root) viewcontroller with a lot of children, or which presents other viewcontrolls, it will make your code really difficult to support, and make something like gode-object.
Listen to George, UINavigationController is the way to go. Your reasons for not wanting to use it are not valid.
However, the reason your code doesn't work might have to do with the unnecessary line after setting the rootViewController to the login vc.
Per Apple's documentation, setting rootViewController automatically sets the window's view to the view controller's view.
this question is very frequent, but I am not able to solve it with any answers available.
I am working on iOS 5.1. My navigation controller is one tab amongst tab bar view controllers. There's a tableview, in which selecting of a row pushes new view controllers.
This problem occurs Only on selecting of the second row and only sometimes. It's not regular.
The Pushed view comes blank - viewWillAppear/viewDidAppear are not being called. On clicking the back button of the navigation bar - the root view's viewWillAppear/viewDidAppear are also not being called, making it blank.
I am pushing the view on select of first row/second row in exactly the same way. But the problem occurs only on the second row.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
switch (indexPath.row) {
case 0:
AViewController *aObj = [[AViewController alloc] init];
aObj.homeObj = self;
[self.navigationController pushViewController:aObj animated:YES];
[aObj release];
break;
case 1:
BViewController *bVCObj = [[BViewController alloc] init];
bVCObj.homeObj = self;
[self.navigationController pushViewController:bVCObj animated:YES];
[bVCObj release];
break;
default:
break;
}
[tableView deselectRowAtIndexPath:indexPath animated:YES];
}
I have tried this and this but in vain.
viewDidLoad is being called on pushing the BViewController, However, viewWillAppear and viewDidAppear is not being called. Following is my viewDidLoad:
- (void)viewDidLoad
{
[super viewDidLoad];
self.view.backgroundColor = [UIColor blackColor];
NSLog(#"nav stack: %#", [self.navigationController viewControllers]);
NSLog(#"nav stack: %#", [[self.navigationController visibleViewController] description]);
//some initialization and call of methods
}
It's not regular. Sometimes I get this scenario, and this continues until I close the app from the background and restart it. But sometimes it works just fine. I am just pushing my view controller to the nab stack.
As I mentioned in the comment, It's a regular navigation controller in tab bar controller.
How are you defining your views for AViewController and BViewController? Generally you'd use initWithNibName, e.g.
AViewController *aObj = [[AViewController alloc] initWithNibName:#"mynibname" bundle:nil]`
As Carl pointed out, you can apparently use just init (though I don't see this documented in the UIViewController Class Reference), but then the system will be very particular about the name of your NIB file. The documentation does say, though, that you can use initWithNibName and pass a nil for the NIB name, in which case it will try to find it for you. Personally, if you're having inconsistent results, though, I'd try using initWithNibName and explicitly pass the name of your NIB, and see if that rectifies the situation.
Or are you building your view programmatically with loadView in your two controllers? Then you need to show us those loadView routines (not to be confused with viewDidLoad).
But according to the documentation, you need to either specify your NIB or use loadView. See the View Management discussion in the UIViewController Class Reference.
Update:
Given your feedback, I have a couple of thoughts:
Needless to say, the problem is apparently not related to the above code. You need to broaden you search and show us more code. Perhaps show us your viewDidLoad of B?
Generally when you don't get these sorts of events, it's because the view controller hierarchy has gotten out of sync with the view hierarchy. The most common way that people do this is if they've done something like "[addSubview someNewController.view]" at some point. If you're using a view controller in any context either than (a) your app delegate's initial configuration; (b) presentViewController (or dismiss); or (c) pushViewController (or pop), then you might want to share what you've done.
As andreamazz pointed out, your comment, "My navigation controller is inside a view controller of the tab bar controller," is a little disturbing if one reads it literally. You can put navigation bar in a view controller's view, but you can't put a navigation controller in a view controller (unless you're doing view controller containment, which is a whole different beast). Equally concerning is where, in another one of your questions, you said, "Embedding a UINavigationController or UITabBarController (my case) in a UIViewController somehow interrupts with the calling of these methods." Thing is, you don't embed nav controllers in other view controllers (unless it is, itself, a container controller such as a tab view controller), but rather its the other way around. But if you literally mean that you have a controller that contains a nav controller, you have to show us how you're doing that (proper view controller containment?) because that's highly unusual.
It's unusual, but I've had projects get corrupted, ending up in weird states. At a minimum, I might suggest "Product" - "Clean" and rebuild. If problem persists, and you've isolated the problem to to B's NIB, then temporarily rename the it and build a quick and dirty one from scratch.
I'm creating a very simple sample app to show how preferences will work with a new application I'm working on. The process is very simple: create a UINavigationController in IB, assign it the View Controller that will be the root view controller, and push a new view controller onto the navigation controller's stack when didSelectRowAtIndexPath is called.
I've read as many related topics to this as I can find and never found a satisfactory answer.
The problem is that when the back button is pressed, the navigation controller animates back, but the view itself doesn't change back, meaning it's not getting popped.
This is the code I use to push the new view controller onto the stack. It's pretty standard. I added the NSLog to make sure it's only getting hit once.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
if(indexPath.section != 0)
return;
NSLog(#"didSelectRowAtIndexPath\n");
PrefsListTableViewController *prefsListTableViewController = [[PrefsListTableViewController alloc] initWithNibName:#"PrefsListTableViewController" bundle:nil];
[self.navigationController pushViewController:prefsListTableViewController animated:YES];
[prefsListTableViewController release];
}
To check if the viewWillDisappear call is hit on the second view, I added this to my PrefsListTableViewController:
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
NSLog(#"ptvc viewWillDisappear");
}
This never gets hit.
First, I was under the impression that you don't need to code anything to handle the back button since the UINavigationController should pop the stack for you automatically when you press the back button. I can show that with a sample app I have which does what I'm doing, but the sample is code only. The code is from Erica Sadun's iPhone Developer's Cookbook code, recipe 11-11. Her code is here:
https://github.com/erica/iphone-3.0-cookbook-/tree/master/C11-Tables/11-Disclosure%20Chevrons
If you look at her code, there are no .xib files, and everything is handled without the need to code the back button at all. The view controllers are pushed in code, and popped, seemingly, without code. I prefer to use .xib files and everything SHOULD be working the same way, but it's not.
Second, I put in NSLog statements to show that in fact, the root navigation controller has the two view controllers.
2011-11-18 11:14:36.355 TableViewTest[58011:207] didSelectRowAtIndexPath
2011-11-18 11:14:36.358 TableViewTest[58011:207] ptvc viewWillAppear (
"<TableViewController: 0x8923d40>",
"<PrefsListTableViewController: 0x8927a20>"
)
2011-11-18 11:14:36.717 TableViewTest[58011:207] ptvc viewDidAppear (
"<TableViewController: 0x8923d40>",
"<PrefsListTableViewController: 0x8927a20>"
)
So you can see that the view controllers are pushed and in the proper order.
That leads to one question: why isn't PrefsListTableViewController getting popped when the back button is pressed? If anyone needs any more info, please let me know.
Have you extended UINavigationController Class? I did and had the same issue. Apparently, according to apple docs, your not supposed to extend that class...
I keep getting the following errors:
2011-04-02 14:55:23.350 AppName[42430:207] nested push animation can result in corrupted navigation bar
2011-04-02 14:55:23.352 AppName[42430:207] nested push animation can result in corrupted navigation bar
2011-04-02 14:55:23.729 AppName[42430:207] Finishing up a navigation transition in an unexpected state. Navigation Bar subview tree might get corrupted.
2011-04-02 14:55:23.729 AppName[42430:207] Finishing up a navigation transition in an unexpected state. Navigation Bar subview tree might get corrupted.
Here is what I am doing. From a view controller, I call the following when a certain button is pushed:
EventsViewController *viewController = [[EventsViewController alloc] init];
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:viewController];
navController.navigationBar.tintColor = [UIColor blackColor];
[self presentModalViewController:navController animated:YES];
[viewController release];
[navController release];
Then, if a certain button is pushed in EventsController, I call:
SingleEventViewController *viewController = [[SingleEventViewController alloc] initWithEvent:[currentEvents objectAtIndex:indexPath.row]];
[self.navigationController pushViewController:viewController animated:YES];
[viewController release];
Then, if a certain button is pushed in SingleEventViewController, I call:
EventMapView* viewController = [[EventMapView alloc] initWithCoordinates];
[[self navigationController] pushViewController:viewController animated:YES];
[viewController release];
So yea, it's obvious that there's nested push animations, but isn't this the right way to go about it? I checked out Apple's DrillDownSave code and this appears to be how they're doing it. Does it matter that I use init methods instead of viewDidLoad methods?
Calling pushViewController before viewDidAppear is unsafe.
ACCIDENTLY TRIGGERING THE SAME SEGUE TWICE
Once in code, and once from interface builder, but both at the same time...
I was getting the same error as the rest of you. Only my problem was I was accidentally firing the same segue, twice. Once from interface builder, and once from within my code.
I have a UITableView. When a cell is selected, a segue in interface builder fires. Heres my problem, I had the segue set up to be directly fired off clicking the CELL ITSELf, inside interface builder, then in my code, I had under didSelectRowAtIndexPath, code that would fire that same segue... like so...
[self performSegueWithIdentifier:#"MySegue" sender:tableView];
That means when didSelectRowAtIndexPath gets called because a row was selected, it fires the segue with the above line of code. Then interface builder, also triggers the segue, because its connected directly to the cell object in interface builder. To stop interface builder from directly firing the segue. You have to connect the segue from the top of the view controller, not nested down inside coming off of the cell itself.
So if you are having this problem for the same reason as me, that is, you are calling the same segue twice, you can fix this by unlinking the connection from the CELL DIRECTLY, to your segue, and having the segue connection originate at the top of the table hierarchy in IB, rather than nested inside the cell. Connect the segue from you View Controller itself, to the segue. If you have done this correct, when you select the segue, it should highlight the ENTIRE view it is coming from, not just the cell.
Now Apples documentation states thus under the performSegueWithIdentifier:sender: reference:
Apps normally do not need to trigger segues directly. Instead, you configure an object in Interface Builder associated with the view controller, such as a control embedded in its view hierarchy, to trigger the segue. However, you can call this method to trigger a segue programmatically, perhaps in response to some action that cannot be specified in the storyboard resource file. For example, you might call it from a custom action handler used to process shake or accelerometer events.
In my case, I have a search button for my UITableView, and whether the segue is called when the search results table is present, or the normal table view is present, had to be determined. So I needed to trigger the segue directly.
So remove the embedded control from interface builder, and just stick it on the view controller itself, then trigger the segue in your code!
Now, no more double segues! And no more errors.
I had the same problem / error message as you did just now, was looking for a solution and ended up at this thread, however, for me I found that the solution is actually having only one animated:YES when doing a nested push (I put animated:YES only for the final push), hope this helps
cheers.
I've figured it out. Apparently if you call -pushViewController from outside of the -didSelectRowAtIndexPath method of a UITableViewDelegate, it doesn't work. Moving the call into that function worked. Weird.
I happened upon this same problem that resulted from a button in a nib being connected to two different actions. It tried loading both view controllers, thereby corrupting the stack.
What do you mean when you say you use init methods instead of viewDidLoad methods?
If you're pushing a new view controller before the old push has bad a chance to be actioned, you will get this sort of error. So putting certain code into init and doing things prematurely could certainly get you the error being reported.
At the point where init is being run on a view controller, the view hasn't been loaded yet!
Um I had this issue, and Im new to the whole iOS dev scene. But after looking at my connections inspector (with file's owner) in the interface builder i saw that as I had copied a button it had the previous buttons method assigned to it as well as the new method I had created. I guess that was where the nested aspect of my problem came from, as it was executing 2 different methods both of which pushed a view onto the Nav Controller. I know this has already been answered but I figured I would put this up just in case anyone else had a silly mistake like mine.
This has already been answered, but I thought this might help others as I got the same error but without using table views. I finally figured out the problem.
I had an existing button whose IBAction invoked a pushViewController. I had created a new button by copying the existing button. The new button also had an action that invoked pushViewController. When the new button was tapped (touch up inside) and the view controller was pushed, I got this error. I deleted the new button, created it from scratch, bound it to the existing outlets and actions, and the error went away.
Ran into the same problem. In my case I was missing a break in the switch statement so two segues were fired at the same time. Easy fix for me.
My problem had to do with the keyboard being active.
This was caused for me by pushing a ViewController from a textField's delegate method:
-(void)textFieldDidBeginEditing:(UITextField *)textField{
FilterLocationViewController *destViewController = (FilterLocationViewController *)[self.storyboard instantiateViewControllerWithIdentifier:#"FilterLocationViewController"];
[self.navigationController pushViewController:destViewController animated:YES];
}
By changing the code to this:
-(void)textFieldDidBeginEditing:(UITextField *)textField{
[_textFieldLocation resignFirstResponder]; //adding this line
FilterLocationViewController *destViewController = (FilterLocationViewController *)[self.storyboard instantiateViewControllerWithIdentifier:#"FilterLocationViewController"];
[self.navigationController pushViewController:destViewController animated:YES];
}
(adding the line [textField resignFirstResponder];) the problem went away.
Basically the lesson is that you shouldn't modify the navigationController stack if the keyboard is out.
Recently, I've faced the same problem. The reason was: -I was trying to pop view controller twice by mistake. you can check this crash by setting breakpoints on push and pop View controllers
1) Perhaps you could try passing the necessary variables as properties before pushing the UIViewController rather than using the init methods with parameters. Most likely you will need these parameters beyond your init method anyway.
Also, in your initWithCoordinates: method you are missing the parameters. Possibly your custom init methods are a part of the problem.
2) Just because you mentioned viewDidLoad -- this method is for initialization after a view has loaded . If you create the UIViewController in code, as it seems you do, you should use loadView to set up your subviews.
This was happening for me because of my UIControlEvents
[button addTarget:self action:#selector(callSecondView) forControlEvents:UIControlEventAllTouchEvents];
I had to change the UIControlEventAllTouchEvents to UIControlEventTouchUpInside or however you want your button to work if you had the issue because of a UIButton call.
My Solution was
[self performSelector:#selector(moveTo) withObject:nil
afterDelay:0.5];
Don't know about other's. I think most of the People using StoryBoard is facing such Problem. I am using XIB.
In my case The Problem Was, when I was moving to another view using push,
I was also using
[self.navigationController popViewControllerAnimated:YES];
in the ViewWillDisappear of the current View at the same time. Just remove it and it works fine.
I was using POP, because of the requirement and the Flow.
The Hierarchy was 1 -> 2 ->3
I was on view 2 and wanted to move to view 3. In that case I encountered this error.
In my case I was both setting the push segue from the storyboard and programatically. Hopefully that'll help anyone
I had this error message too, and the navigation bar and navigation controller transitions were weird. My setup was a bunch of Navigation Controllers embedded in a Tab bar Controller. The problem was that I didn't call super.viewDidLoad() in my Tab bar Controller implementation of viewDidLoad.
Calling super is something the docs clearly point out that you should do when overriding viewDidLoad, and I learned this the hard way.
Maybe this can help someone else too!
I know that this was answered, but it could help others.
I had the same problem, but it was caused because I was using a bad event for an info button.
I was using "UIControlEventAllTouchEvents" and this generated two push of the same view into the navigation controller. The correct event was "UIControlEventTouchUpInside". I'm new to iOS.
This resolves the problem:
https://github.com/nexuspod/SafeTransition
If you push (or pop) a view controller with animation(animated:YES) it doesn't complete right away, and bad things happen if you do another push or pop before the animation completes.
To reproduce this bug, try pushing or popping two view controllers at the same time. Example:
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
UIViewController *vc = [[UIViewController alloc] init];
[self.navigationController pushViewController:vc animated:YES];
}
You will receive this error:
2014-07-03 11:54:25.051 Demo[2840:60b] nested push animation can
result in corrupted navigation bar 2014-07-03 11:54:25.406
Demo[2840:60b] Finishing up a navigation transition in an unexpected
state. Navigation Bar subview tree might get corrupted.
Just add the code files into your project and makes your navigation controller as a subclass of APBaseNavigationController, and you'll be good to do.
Just to complete the list, here is another reason which can cause "nested push animation can result in corrupted navigation bar":
I did setup several NavigationController within a TabBarController and set
the selectedIndex within the storyboard Identifiy Properties. After moving active Tab to Code error disappeared.
I have a strange issue going on which I can't fathom. I have a number of uiViewControllers which I'm pushing onto a NavigationController - all fairly regular stuff. It's a bit of a drill-down application so after you've moved through 3 screens, the next view to be pushed doesn't actually appear - only the title changes in the Nav Bar. I'm pushing it the same way as all the others:
DisplayViewController *tempDispController = [[DisplayViewController alloc] initWithNibName:#"DisplayVC" bundle:nil];
[self.navigationController pushViewController:tempDispController animated:YES];
[tempDispController release];
The new title is set in the ViewDidLoad of the new ViewController - and that does animate in, but the actual view is still the old one.
EDIT: Forgot to say that it does load fine occasionally. Usually the first time but then not the next few times. Sometimes not even the first time.
Any ideas?
Thanks..
It sounds like the view controller is being pushed onto the stack, but its view has no content.
Solved it.. the viewController calling it was running a synchronous network call which hadn't completed by the time I was calling the next viewcontroller..
So, just made it an asynchronous connection and waited for the response before moving on. Also makes it better for showing progress to the user - and error handling.
Thanks for the responses though!