I have a question about UINavigationController.
I have create a project with storyboard using skd 7.
In my storyboard I have add a first NavigationViewController cnnected to TabBar Controller.
Now, into every ViewController of my TabBar I would to set the title...
In a first time I have try to set the title using:
[self setTitle:#"my title"];
But I can't to see the title..So, I have try with this (int a ViewDidLoad method).
self.navigationController.navigationBar.topItem.title = #"My title";
In this way I can see my correct title..but I can not figure out ...why?. What is the best way or the correct way to assign the title to my controller dynamically?
The correct answer is this self.navigationController.navigationBar.topItem.title = #"My title"; because you in order to change a title for a view that is pushed via UINavigationController you have to inform the navigation controller to do so.
Without the navigation controller, the other would be the correct answer. The issue here is that even without the navigation controller the first view in the nav controller should get UITabBarItem title.
So in my universal app I have a section where a person can look at an existing list of notes from our system (retrieved through a simple web service) and then also create a new note if they want. So for the iphone it's pretty simple layout, a TableViewController for displaying the list with a "Add" button on the NavigationBar that presents the modalview for adding the new item. On the iPad though, the same layout has a lot of wasted space so I opted to go with the popOver method to show the list in a popOver and then let them add from there. My problem is that when the user clicks on the Add button within the PopOver view, the modal view comes up full screen instead of just coming up within the popover view. Here's the code I have so far:
-(void) AddButtonPressed:(id)sender {
NewNoteVC *newNote = [[[NewNoteVC alloc] initWithNibName:#"NewNoteVC" bundle:nil] autorelease];
newNote.defaultClientID = defaultClientID;
UINavigationController *navCon = [[[UINavigationController alloc] initWithRootViewController:newNote] autorelease];
if ([isPopOver isEqualToString:#"YES"]) {
[navCon setModalInPopover:YES];
[self.navigationController setModalInPopover:YES];
[self.navigationController presentModalViewController:navCon animated:YES];
}
else {
[self.navigationController presentModalViewController:navCon animated:YES];
}
}
The "isPopOver" string is just a placeholder sent from the previous screen that called this TableView (I know I can switch this to a boolean for better performance I just put this together real quick to try it out). I know I messed up somewhere, I just don't know what setting I need to get this working correctly.
You need to define the view controller's modalPresentationStyle to be "current context".
navCon.modalPresentationStyle = UIModalPresentationCurrentContext;
This will result in modal view controller filling the popover like the popover's root controller.
Try using the presentViewController:animated:completion: instead of presentModalViewController:animated: and set self.navigationController.definesPresentationContext = YES
I'm creating a library which will add a view at the bottom of the application (when my library is integrated in application).
I'm using view controller's view's frame parameter to get the size of the view and calculation my library's view frame according and showing it.
The problem is that when navigation bar is there, my view is going still below the actual view visible. So, i want to know whether current view controller is based on navigation controller or not and whether navigation bar is visible in that view or not. how can I find that?
I'm late with the reply, but for other persons who try to do the same thing (like me :D).
This code may solve your problem:
id nav = [UIApplication sharedApplication].keyWindow.rootViewController;
if ([nav isKindOfClass:[UINavigationController class]]) {
UINavigationController *navc = (UINavigationController *) nav;
if(navc.navigationBarHidden) {
NSLog(#"NOOOO NAV BAR");
} else {
NSLog(#"WE HAVE NAV BAR");
}
}
UINavigationBar inherits from and has all the fine properties and behaviors of UIView and one of these properties is hidden.
So for your view, if you can get a handle to your navigation bar, all you need to do is check to see if hidden is YES or NO.
one way to do this would be to have a UINavigationController property or accessor (setter & getter) for your library so whoever makes use of the library can set the navigation controller and/or bar on your library's behalf.
Up to date check from a view controller context:
let navHidden = navigationController?.isNavigationBarHidden ?? true
if needsCloseButton || navHidden
{
// here add an alternative ways to get out since back button is not here, say add a close button somewhere
My app is based on a tab bar architecture. In order to have an easy internationalisation mechanic, I do not write any string in XIB files. viewdidload permits to change programmaticaly the strings in the views.
When my app launches, I can see the 4 tabs. But in fact only the first one loads its view controller. The others wait for user click to be loaded.
Tabs title can be changed using [self setTitle:#"Mouhahaha"]; in viewDidLoad of loaded view controller.
If I want to keep my internationalisation mechanic available, I do not set in my XIB the name of tabbar items. But, as at start all tab' view controllers are not loaded, I have blank titles for some tabs. The right title is set only when the user click on the tab.
I am looking for a way to set this title programaticaly for each tabbaritem. Do you have hints ?
Thanks a lot.
kheraud
my preferred method of doing this programmatically together with the storyboard is to make a subclass of UITabBarController, have my tab bar controller scene in my storyboard use the new subclass (with 3 UIViewController relationships from the tab bar controller to the desired view controller in the case below), and then override viewWillAppear:
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
NSArray* titleKeys = [NSArray arrayWithObjects:#"top places",
#"localizablekey1",
#"localizablekey2",
#"localizablekey3",
nil];
[super viewWillAppear:animated];
int count = 0; for (UIViewController* viewController in self.viewControllers)
viewController.tabBarItem.title = NSLocalizedString([titleKeys objectAtIndex:count++], nil);
}
All you need to do is make an instance of UITabBarController, then alloc any views you want in it, then set the UITabBarController views. Make sure that your TabBarController is the one that is visible. Also make sure that any viewControllers you want in your tab bar are being imported with #import.
UITabBarController *c = [self tabBarController];
SecondViewController *s = [[SecondViewController alloc] init];
[s setTitle:#"Whatever"];
c.viewControllers = [NSArray arrayWithObjects:self, s, nil];
[s release];
Put this in the viewDidLoad method of the first controller allocated.
Alternatively you could just change the way your ApplicationDelegate sets up the TabBarController, but i won't go into that.
Hope this helps
What does this error indicate:
"Popovers cannot be presented from a view which does not have a window."
the thing that saved my life:
if (self.view.window != nil)
[popoverController presentPopoverFromRect:CGRectMake(44, yCoord, 111, 111) inView:self.view permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES];
by adding if condition it doesn´t crash anymore. I don´t really get it because the presentPopoverFromRect function is ALWAYS called. There is no situation where window would be nil but anyway it did the trick.
edit: I have this code in viewDidAppear.
Nevertheless in most cases it's enough to move presentPopoverFromRect to viewDidAppear or didMoveToWindow but in my case for some reason the if condition was necessary.
the view you're adding the popover to has to already have been added to a window with the "addSubview:" method.
Try waiting until
- (void) didMoveToWindow
is called for the view and then load the popover
I got this problem.
I had a UITabBarController as the detail view, and I set the barButtonItem as the leftBarButtonItem on all three navigation controllers in the tab bar.
vcChart.navigationItem.leftBarButtonItem = barButtonItem;
vcAnalysis.navigationItem.leftBarButtonItem = barButtonItem;
vcTechnicals.navigationItem.leftBarButtonItem = barButtonItem;
Turns out only the last one added is valid, and the previous two would throw the exception when tapped on.
To fix it, I only set the leftBarButtonItem for the visible view controller, and just switched the barButtonItem to the visible view controller every time the user switched tabs.
Just encountered this issue. Turned out that the inView: parameter was using an IBOutlet that wasn't connected in IB. Thus, an attempt was made to launch the popover in nil. That doesn't work.
So, make sure you are using a valid view.
There are many ways to get to this error. Basically you need to wait to call the presentPopover command until your calling view is added to a window. I did it this way.
- (void)viewDidAppear:(BOOL)animated
{
[self methodThatDisplaysPopOver];
}
My presentPopoverFromRect call is inside my methodThatDisplaysPopOver function.
You could protect every presentPopover call like MobiMaciek suggests with this.
if (self.view.window != nil)
[popoverController presentPopoverFromRect:CGRectMake(10, 10, 100, 100) inView:self.view permittedArrowDirections:UIPopoverArrowDirectionUp animated:YES];
However, I think it would be better to understand when self.view.window gets assigned and make sure that you present you popover after the view has a window.
I received the same error message when assigning the same UIBarButtonItem to multiple navigation items as did Lewis. My example was slightly more complicated as I was using a UISplitViewController.
In my RootViewController I have an array of arrays to accomplish multiple sections within my table. Each time that the user clicks a row in the table, a new "detail" view controller is placed in the right pane of my splitViewController. Prior to setting the leftBarButtonItem = nil, I would receive a segfault after 3-4 clicks of the "Menu" button with the same error as a111. I updated my code to actually retrieve the previous detail view controller and set the leftBarButtonItem item to nil.
allData is my NSMutableArray that contains several other NSMutableArrays as objects.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
// Retrieve the new detail view controller
UIViewController *detailViewController = [[self.allData objectAtIndex:indexPath.section] objectAtIndex:indexPath.row];
// Add the detail view controller to a navigation controller and set the bar style
UINavigationController *detailNavigationController = [[UINavigationController alloc] initWithRootViewController:detailViewController];
detailNavigationController.navigationBar.barStyle = [[NSUserDefaults standardUserDefaults] integerForKey:#"UIBarStyle"];
// Retrieve previous detail view controller and remove the leftBarButtonItem
UINavigationController *previousDetailNavigationController = [splitViewController.viewControllers objectAtIndex:1];
UIViewController *previousDetailViewController = [[previousDetailNavigationController viewControllers] lastObject];
previousDetailViewController.navigationItem.leftBarButtonItem = nil;
// Update the split view controller's view controllers array.
NSArray *viewControllers = [[NSArray alloc] initWithObjects:self.navigationController, detailNavigationController, nil];
splitViewController.viewControllers = viewControllers;
[detailNavigationController release];
[viewControllers release];
// Dismiss the popover if it's present.
if (popoverController != nil) {
[popoverController dismissPopoverAnimated:YES];
}
// This sets the left bar to nil when in landscape and equal to "Menu" when in portrait.
// We need to remove rootPopoverButtonItem from the previous viewController...
detailViewController.navigationItem.leftBarButtonItem = rootPopoverButtonItem;
}
The error message was slightly deceiving at first but the answers above helped me out. I wonder why I could click the "Menu" button up to 3-4 different times before the segfault... I'll investigate further.
This error also occurred when the inView: Parameter is incorrect - to test try self.view
yes, you are right but still we can add subview from parent class in it. so it can be represented from a view which have a window:
[popoverController.contentViewController.view addSubview:mySubView];
I had the same error message as the OP, in a very similar situation to that reported by TPoschel, except I had a split view controller with an embedded tab bar controller in the detail pane, and a navigation controller within this. The bar button item is added as the navigation bar leftBarButtonItem.
Only on iOS5.0 (not 5.1) does it seem to require you invalidate the bar button item on the tab bar you are leaving by setting it to nil. Before then adding the bar button to the navigation bar on the tab you are going to.
If I don't do that, from debugging my own code, the window property of the bar button item stays set to nil, and causes the exception, on returning to a screen you'd previously been to. I'm guessing as a side effect of setting the leftBarButtonItem in the navigation item, it goes off and sets the frame. But it doesn't seem to bother unless the button is different from what is currently set there. Hence, the need to set it to nil when leaving a tab, even though it is technically the same button that's being passed around.
I would upvote TPoschel's answer, except SO won't let me.
I had a problem like this. Received this message when clicking a customized UIBarButton item that invoked a selector method with did performSeque.
The problem was my segue was still attached to the UIBarButton item. It should have been attached to the main view of of the view controller. Changed this and worked fine.
P.S., all this got started because I wanted to add and "info" button to my UIToolBar. This isn't one in the system provided list and should be.
There will be a view from which you asks to display your popover.The reason for this error is because you didn't made this view as a subview of the window.
[self.view addSubview:displayPopOverVC];
where displayPopOverVC is the view controller from which the popOver appears
i had the same problem, after adding PresentPopOver in viewDidAppear this was solved
- (void) viewDidAppear:(BOOL)animated{
CGRect popoverRect = screenBounds;
popoverRect.size.width = MIN(popoverRect.size.width,0) ;
popoverRect.origin.x = screenBounds.origin.x;
[popoverController
presentPopoverFromRect:popoverRect
inView:self.view
permittedArrowDirections:UIPopoverArrowDirectionAny
animated:YES];
}
this was happening as inView:self.view should be called after viewDidLoad as suggested by #hey68You and MobiMaciek..
I replaced
[actionSheet showFromBarButtonItem:self.navigationController.navigationItem.leftBarButtonItem animated:YES];
with
[actionSheet showInView:self.view];