I have a navigationBar, with a UIImage on it's title, like this:
self.navigationItem.titleView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"top_logo.png"]];
When i select a row, the "back" button does not appear. Why?
I have the exact same code on other's viewControllers, and it appears.
I don't understand why...
Thanks,
RL
The back button won't appear unless you've set self.navigationItem.title or 'self.title' in the previous view controller on the stack (parent VC) or explicitly created a UIBarButtonItem and set it to self.navigationItem.backBarButtonItem in the previous view controller on the stack (parent VC).
did you push the new view through the navigation stack?
like:
[self.navigationController pushViewController:viewControllerToPush animated:YES];
Related
I'm using the following code to try to make a "back" button for my app, the view that this code is located is in a modal view (if that has any bearing?):
navBar = [[UINavigationController alloc] initWithRootViewController:tvController];
[navBar.view setFrame:CGRectMake(0, 0, 320, 460)];
self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle: #"Back"
style: self.navigationController.navigationItem.leftBarButtonItem.style
target: self
action: #selector(backAction)];
navBar.navigationItem.backBarButtonItem.enabled = YES;
[self.view addSubview:navBar.view];
The view does not show at all, thank you for any tips!
EDIT: Even if I use a leftBarButtonItem, it still does not show up, I think there is some problem with the self.navigationItem bit of my code?
You need to make sure that when you present the modal view that you wrap it in a UINavigationController, then you'll have a valid navigation bar to manipulate. Otherwise you'll change the navigationItem all you want but it won't show up because you're not in a navigationController.
So when you go to present the view controller you're probably doing something like this.
SomeViewController *someViewController = [[[SomeViewController alloc] init] autorelease];
[self presentModalViewController:someViewController animated:YES];
What you want to do is present it like this
SomeViewController *someViewController = [[[SomeViewController alloc] init] autorelease];
UINavigationController *navigationController = [[[UINavigationController alloc] initWithRootViewController:someViewController] autorelease]
[self presentModalViewController:navigationController animated:YES];
Then when you're in the modal view you'll have a valid navigation bar that you can manipulate. Altering the leftBarButtonItem at that point will actually do something and be visible.
If you're trying to make this show a back button though you're probably "doing it wrong" typically if you're presenting something modally like this you'd show a "done" button. However by wrapping this with a navigation controller like this it does allow the modal view to then push and pop view controllers and operate as a normal navigation stack. But the root of it should probably have a "done" button not a back to return back to its previous state.
The backBarButtonItem property needs to be defined on the previous item in your stack, i.e. on the view controller you are going back to, not the current one.
EDIT:
OK, I see now you are adding your own custom navigation bar. In that case, you cannot use the view controller's navigation item. You must instead push your own navigation items on to the navigation bar and access those instead. For example:
UINavigationItem *item = [[UINavigationItem alloc] initWithTitle:#"Back"];
item.leftBarButtonItem = ...;
[navBar pushNavigationItem:item animated:NO];
When I try to present a modalViewController, it covers up my navigation controller's navigation bar. Any tips? Thanks.
UPDATE (with code):
ComposeText *compText = [[ComposeText alloc] initWithNibName:#"ComposeText" bundle:[NSBundle mainBundle]];
compNavController = [[UINavigationController alloc] initWithRootViewController:compText];
UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:compNavController action:#selector(compDoneTapped:)];
compNavController.navigationItem.rightBarButtonItem = doneButton;
[self presentModalViewController:compNavController animated:YES];
compText.title = #"Compose";
[doneButton release];
Everything seems to be in order, but the button is still not appearing on the navigation bar.
That's what it is supposed to do. If you want a navigation bar, present a new UINavigationController modally and set it's root view controller to your modalViewController.
The question you need to ask yourself is: "why do I want to show my navigationbar". If it is to give the user access to some buttons then it is the wrong reason. Modal view controllers are there to take full control of the screen and to not allow the user to manipulate anything else in the app until the controller is dismissed. If you don't want that do as Cyprian suggests and push a viewcontroller on your navigation stack.
If it is just a visual thing (logo ...) duplicate it in your modal view controller.
UINavigationController has it's own method to show another viewController.
-(void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated
It uses stack, to push new viewController so it can handle its navigation with buttons.
I know that it could seem strange but i need to add a back button on the navigation Bar of the first navigationController's view. I tried like this:
UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:#"Foo" style:UIBarButtonItemStyleBordered target:self action:#selector(foo:)];
self.navigationItem.backBarButtonItem=backButton;
if instead of backBarButtonItem i write leftBarButtonItem the button is showed. My problem is that i need an arrow button as the normal back button. Is this possible?
Usually this works out of the box, but sometimes with modal views / action sheets you may need this. Just before you instantiate your viewcontroller and push it onto navigationcontroller stack, try
UIBarButtonItem *newBackButton = [[UIBarButtonItem alloc] initWithTitle: #"Back" style: UIBarButtonItemStyleBordered target: nil action: nil];
[[self navigationItem] setBackBarButtonItem: newBackButton];
[newBackButton release];
DetailViewController *detailVC = [[DetailViewController alloc]init];
[self.navigationController pushViewController:detailVC animated:YES];
[detailVC release];
I don't think you can do that on the first NavigationController view, because you need to set the backBarButtonItem property in the parent controller, before the child controller is pushed. Also, according the to the Apple docs, the target & action of the backBarButtonItem must be nil.
This question about creating a left-arrow button on a UIToolbar may give you some ideas of how you could work around this using a custom image (for the leftBarButtonItem).
or you could also do the following - I prefer this method. I got this from a different post.
Use following psd that I derived from http://www.teehanlax.com/blog/?p=447
http://www.chrisandtennille.com/pictures/backbutton.psd
Then I just create a custom UIView that I use in the customView property of the toolbar item.
Works well for me.
Hope that helps a little
Of course you can do this. You just need to change the leftBarButtonItem's title to back
then you will get a nice left arrow button with the title back. Then you just change the selector to actually perform a method when the button is clicked. So #selector(foo:)
Here some code on how to achieve the above:
self.navigationItem.leftBarButtonItem.style = UIBarButtonItemStyleDone;
self.navigationItem.leftBarButtonItem.title = #"Back";
self.navigationItem.leftBarButtonItem.target = self;
self.navigationItem.leftBarButtonItem.action = #selector(endTextEnteringButtonAction:);
Let me know if that helps.
Apple Document says:
When this navigation item is immediately below the top item in the stack, the navigation controller derives the back button for the navigation bar from this navigation item.
So If your navigation item is the top of the Stack (as we are talking here) you can't add the back button to the navigation controller, simply because no place he can navigate back to it because it's the top item in the stack.
Updated Answer :
After I searched I found work a round to make a back button in your root view controller in Navigation controller in these link
It's very simple :)
[self.navigationItem setHidesBackButton:YES animated:YES];
UIBarButtonItem* backButton = [[UIBarButtonItem alloc] initWithTitle:#"Start" style:UIBarButtonItemStyleBordered target:self action:#selector(initializeStuff)];
self.navigationItem.leftBarButtonItem = backButton;
In my application, I'm launching a modalViewController on rightbarbutton click of navigationbar. This modalViewController overlaps the navigationbar. I tried setting its frame but it remained the same. I want to display navigationbar even if modalViewController is still there.
EDIT: I call the following method on navigationcontroller's rightbarbutton press. The view appears properly but the position is not right.
-(void)showViewForPosts{
self.navigationItem.backBarButtonItem =
[[UIBarButtonItem alloc] initWithTitle:#"DISMISS"
style: UIBarButtonItemStyleBordered
target:self
action:#selector(dismissViewCOntroller)];
displayController = [[UIViewController alloc]initWithNibName:nil bundle:nil];
displayController.view.frame = CGRectMake(0.0, 150.0, 320, 436);
displayController.view.backgroundColor = [UIColor blueColor];
//I'M ADDING DIFFERENT VIEWS HERE
[self presentModalViewController:displayController animated:YES];
}
Thanx in advance.
Do you need it to be the same navigation bar?
In my app, there is another NavigationController for the modal view flow, ie going from a modal view to another. This feels more consistent to me, since 'modal' means taking (temporary) exclusive access to screen and inputs, whereas navigation on iPhone is stacking views.
For some reason, if I try to go back to the main menu using the back button on the upper left corner, only the title returns to the previous menu, but not the view controller. View controller would return to the previous menu only if I explicitly call popViewControllerAnimated using some other button.
Is there anyway to solve this? I think I've coded something wrong. Tried googling but couldn't find any cases like mine.
I'm getting the exact same problem. Here is my code:
- (IBAction) showGameView:(id) sender {
gameView = [[TCGameViewController alloc] initWithNibName:#"TCGameViewController" bundle:[NSBundle mainBundle]];
[self.navigationController pushViewController:gameView animated:YES];
[gameView release];
}
And when I am done with gameView, I do this:
[self.navigationController setNavigationBarHidden:NO animated:YES];
But all it does when I push the 'back' button is cycle through the navigation bar, but never pops the view. I don't even know how to debug it.
In my other view, "infoView" I call the same code as before except the NavBar is never hidden, but it works just fine.
helps!
This problem can occur when you override the following method in your custom view controller:
- (UINavigationItem*)navigationItem
But you don't specify a UIBarButtonItem for the leftBarButtonItem property of the returned UINavigationItem.
If you use a custom navigationItem, and want the standard back button functionality, you could add a method as follows (remember that every UIViewController has a reference to the navigationController that containts it):
- (void)backButtonTapped
{
[self.navigationController popViewControllerAnimated:YES];
}
And then setup part of the custom navigationItem as follows:
- (UINavigationItem*)navigationItem
{
UIBarButtonItem* newLeftBarButton = [[UIBarButtonItem alloc] initWithTitle:#"Back"
style:UIBarButtonItemStyleBordered
target:self
action:#selector(backButtonTapped)];
UINavigationItem* navigationItem = [[[UINavigationItem alloc] init] autorelease];
Hope this helps.