I am having problems whereas I lose autofocus for ZBarReaderViewController exactly like is asked and answered here. The apparent solution is to release the UIImagePickerController after use. However, I am using ARC and cannot figure out how to release it. I have tried...
-(void)viewWillDisappear:(BOOL)animated{
self.imagePicker=nil;
[super viewWillDisappear:animated];
}
however this does not appear to work. imagePicker is an instance of UIImagePickerController.
I will mention that this may be a symptom of a bigger problem. I am presenting the modal view from a customized tab bar that is pushed on a navigation controller from a selected table view cell.
Navigation controller>table view>accessory button on cell>push custom tab bar controller.
In order to present the modal view over both the bottom tab bar and the top navigation bar, I am presenting from the navigation controller like...
BIDAppDelegate *appDelegate=(BIDAppDelegate *)[[UIApplication sharedApplication]delegate];
[appDelegate.navController presentModalViewController:imagePicker animated:YES];
I think this is causing problems when I receive memory warnings, but I was going to try and address the ZBar autofocus issue first and see if that addresses any other problems.
Thanks in advance for any assistance.
Related
I recently started using interface builder, the problem i'm facing right now is when i use the back button of navigation controller, my UI elements' y axis go up by roughly 20-30 px, is there some setting i've to use to avoid this problem ? And they go up only when i use pushViewController, when i use popViewController it loads the way i need.
Code i'm using for pushing:
examVC=[[ExampleClass alloc] initWithNibName:#"ExampleClass" bundle:nil];
[[self navigationController] pushViewController:examVC animated:YES];
I'm attaching the images with the question. Please note how label has gone down about 20-30 px.
Why does this happen? What am i doing wrong ?
Thanks for all the help.
Edit : changed the screens for better clarity
I'm using pushing code on the round rect button.
Screen 1:UI elements set in my IB
Screen 2: How it looks when pushed from previous view
Screen 3: How it looks when popped from the "Next View"
My home view controller had the navigation bar hidden, the screen i posted was the second view which comes after the home view. I wanted to hide navigation bar in the first view only, so i had used :
- (void)viewDidDisappear:(BOOL)animated
{
[self.navigationController setNavigationBarHidden:NO animated:animated];
[super viewDidDisappear:animated];
}
It caused the problem because i was showing the navigation bar again in viewDidDisappear, so the view would load first then the navigation bar would be shown causing it to overlap.
So i put the same code in viewWillDisappear, which removed the issue. As navigation bar did load before loading of the next view. Now the view loads just like i designed it in interface builder.
Hey I don't know whether it will work for you or not but in your IB change top bar None to Navigation Bar
Then adjust your element accordingly and tun the code.
I tried all of the suggestions here and none of them worked. My UI elements were always lower when popping back to my original view controller. The only thing that fixed this for me was going into my nib file in Interface Builder and turning off Auto Layout.
I have a Navigation controller in a storyboard, currently with two screens. Screen1 contains an opening logo and some buttons, and I have hidden the navigation bar at the top using:
[[self navigationController] setNavigationBarHidden:YES];
in viewDidLoad and viewWillAppear: (in viewWillAppear I have it set with animated:YES, so it slides off when coming back from other screens).
When I go to Screen2, I have:
[[self navigationController] setNavigationBarHidden:NO animated:YES];
in the first view controller's viewWillDisappear, and the navigation bar slides in all nicely when that view comes on to the top of the navigation stack.
Problem is, when I tap back, the navigation bar animates off the right side of the screen, but Screen2 stays there, revealing another navigation bar underneath!
I can then tap back again and it will push Screen2 off and the main screen shall return, but this is not behaviour I want to pass on to any users, obviously!
Anyone had this issue before, or have any points on what might be the culprit?
Edit: I just found an error appearing when I run the iOS Simulator:
2011-11-02 19:29:13.548 TestHTML5[10261:f803] Unbalanced calls to begin/end appearance transitions for <LessonViewController: 0x6c5e960>.
This happens when I click the button to go the the second view (LessonViewController).
Hopefully that might be the thing to crack this, anyone know?
I found my IBActions, which contained:
SecondViewController *X = [self.storyboard instantiateViewControllerWithIdentifier:#"X"];
[self.navigationController pushViewController:X animated:NO];
on each were causing the view to double up or something like that. When I commented these two lines out in each IBAction, the problem disappeared.
Thanks heaps to #CodaFi for helping me through possibilities for this, to be honest, this solution doesn't make sense to me, even thought I can see it working here.
I'm writing my first iPhone app and I am trying to figure out how to have a MasterView and DetailsView like in the example. However, instead of using a TableView, I want to use a button on the MasterView to go to the SignUpView. I want the MasterView to NOT have a navigation bar but the SignUpView needs to have one.
I have tried putting a NavigationController into the MasterView using the interface builder. This doesn't seem to do anything at all ... I.e. I make the following call:
[self.navigationController pushViewController:signUpViewController animated:YES];
And nothing happens. The SignUpView is never shown.
So then I declared a NavigationController in the AppDelegate. The above call in the same function that it was in before (button handler, button is in MasterView) works now! It takes me to the SignUpViewController.
however, the issue is, when I press back on the navigation bar in the sign up view, the navigation bar shows up again in the MasterView. I tried to set
self.navigationController.navigationBarHidden = YES;
in viewDidLoad and viewDidAppear, but that causes a black bar to appear in the transition from SignUpView to MasterView.
I tried to not set it in one of the two, and that causes the animation to go smoothly, but the navigation bar shows up in the MasterView.
I feel like this should be pretty simple to do ... but I'm at my wits end trying to figure this out. Some help would be really appreciated!
Thanks.
Probably not the answer to your question, but just a small suggestion. In the many apps that I have come across, a sign-up/sign-in view is generally displayed as a modal view (on top of your master view) with a 'cross' in the top-right corner to dismiss it. Probably it results in a better user experience.
Also, did you try self.navigationController.navigationBarHidden = YES; in the MasterView's viewWillAppear ?
HTH,
Akshay
I had this problem too, until I discovered setNavigationBarHidden. You will probably want to use these in viewWillAppear/viewWillDisappear or viewDidAppear/viewDidDisappear. You don't want to call this in viewDidLoad because that is only called once when the view is initialized, not every time it appears.
To hide:
[self.navigationController setNavigationBarHidden:YES animated:YES];
To show:
[self.navigationController setNavigationBarHidden:NO animated:YES];
This is the situation:
I have a tab bar with 2 tabs. Tab01 and Tab02.
In Tab01 I have a button which pushes repVC:
repVC.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
[self presentModalViewController:repVC animated:YES];
[(UIViewController *)[tabController.viewControllers objectAtIndex:0] setView:repVC.view];
[repVC release];
Inside repVC I have another button which pushes an MFMailComposerViewController:
MFMailComposeViewController *mail = [[MFMailComposeViewController alloc] init];
[self presentModalViewController:mail animated:YES];
[mail release];
The problem is: when mailView is shown(in Tab01) and I click Tab02, then back to Tab01, the mailView is hidden and even if I click the email button again, the view won't be presented.
So what I have is: Tab01.view -> repVC.view -> mail.view
For repVC, I use this line when I push the view so that even if I go switch tabs, that view will still be activated:
[(UIViewController *)[tabController.viewControllers objectAtIndex:0] setView:repVC.view];
But I can't do the same for mail because tabController is declared in another class which I cannot import. So I can't access the tabController and set the view for Tab01.
Hope the edit helped the understanding.
Hmm,
I still would suggest to use a Navigationcontroller. Would make things way easier, is conform to apple guidelines and suggestions and is pretty fast implemented. (Just create a Navigationcontroller, put the View of Tab1 as main view and hand it over to the TabbarController. Then for the mailView use [self.navigationController pushViewController:mail animated:YES]; Then the navcontroller "saves" the present view for you when u switch tabs)
But if for some Reason you have to use a modalViewcontroller you could either just deactivate the tabbar while the ModalView is shown or try to implement a switch or a simple if...else case in your ViewWillAppear where u check what screen to load.
Then Clean out the Window and load the right screen.
Hope you get the idea of what I mean, sometimes my way of writing seems to confuse people. ^^
A little more information would be great.
How did u set up your TabbarController?
How do u push the new view? Within a UINavigationController? If not, then do it with a navController, he should save the actual state of view and your problem should be solved.
If u already use a navController please post your ViewDidLoad and ViewWillAppear of the Viewcontroller of Tab 1
As #Amandir points out you could probably solve your problems by using a UINavigationController. I get a feeling that you are trying to abuse the modal view controller concept a bit and that's why it doesn't work as you expect. When you use presentModalViewController:animated: the intention should be that you are displaying a view that is modal, i.e. the user must interact and dismiss the modal view before she can continue.
What the paragraph above means that when you present a modal view controller it shouldn't be possible to use the tab bar. Since you are using the word push I'm guessing that you would like change the view of Tab01 while still being able to use the functionality of the tab bar. The problem is that there isn't any built-in method of pushing view controllers besides UINavigationController. persentModalViewController:animated: should only be used in case where you want a modal view, which on the iPhone means a full screen view.
The easiest way would probably be to use an UINavigationController and hide the navigation bar. Then you would get the functionality I think you are after. The other option is to manually add and remove sub views.
[self.view addSubview:repVC.view];
and
[repVC.view removeFromSuperview];
[self.view addSubview:mail.view];
You can use block animations if you want some fancy transitions.
I'm having a very strange problem with the UINavigationController.
I found a very similar question here:
UINavigationController not popping UINavigationBar items
but the solution there had to do with the fact that the guy had added a category to NSMutableArray, and I'm not doing anything like that.
In short, the problem is this: I have a navigation controller and I'm pushing a few view controllers on it. Then when the 'back' button is tapped the view controller is popped, but the corresponding navigation item isn't. If I tap back again, then the navigation item is popped.
Besides, it only happens when using the back button from the navigation controller's navigation bar. If I call popViewController explicitly (for example from a button press), it works as expected.
And this only happens on my iPad running OS 3.2, but not on my iPod Touch running OS 3.0 or on the simulator.
I've been trying to isolate the problem in a separate project from the rest of my app so I can experiment with it, but I can't get it to reproduce, though it occurs 100% of the times on specific views in my app.
I know that's not nearly enough information to get an specific answer, but I just wanted to know if anyone ever heard of a navigation controller not popping the navigation items as expected, just so I could have some clue as to where to investigate next.
Here's an example of the code I use to push a view controller, it's pretty straightforward, I'm not trying to do anything special with it:
// pushing a view controller from a button press (set up with interface builder)
- (IBAction) tappedExtras
{
ExtrasViewController *controller = [[ExtrasViewController alloc] initWithNibName:#"ExtrasViewController" bundle:nil];
[self.navigationController pushViewController:controller animated:YES];
[controller release];
}
note: in that example I'm using a custom view controller class called ExtrasViewController, but the problem happened with any kind of view controller I tried.
And here's a bit of code used to pop the view controller explicitly, also triggered by a button press set up with interface builder:
- (IBAction) cancelChanges
{
userCancelled = YES;
[self.navigationController popViewControllerAnimated:YES];
}
this works perfectly (popping the view controller explicitly), but on the exact same view controller if instead of tapping the button set up with interface builder you tap the back button on the navigation bar, the navigation item is not popped correctly.
I got the same issue with navigation that subsist after poping the third level pushed view controller.
The issue only appear in landscape on iPad. No issue on the iPhone (3.1.3 & 4.0). Of course, it's ok on the simulator.