i'm searching for a way to disable a TabBarItem from within the ViewController of one of the TabBars Tabs. I'm even not sure if this is about the View Hierarchy or what to really search for. I tried a lot but didn't come up with a solution.
Right now I worked arround it by saving a reference to the tabbar in a singelton object when instanciating the tabbar (inside the apps delegate). But I don't think this is the best way to do it.
Thanks and Cheers,
Nils
I had the same problem and I have found a solution (but I find it a little bit dirty)
In your ViewController where you want to disable the TabBarItem, create a variable UITabBarController *myTabBarController; with property.
In the class where you manage your Tabbarcontroller put this code in the viewDidLoad:
MyViewController * vc = (MyViewController *)[navigationController.viewControllers objectAtIndex:0];// O the index of the first view controller replace it with the index of the needed viewController
vc.myTabBarController = myTabBarController; // pass your TabBarController to your ViewController
Now back to your ViewController class (MyViewController) and use this code to disable the tabBarItem:
UITabBarItem *mapTabBarItem= [[myTabBarController.tabBar items] objectAtIndex:1]; // I want to desable the second tab for example (index 1)
[mapTabBarItem setEnabled:NO];
Note that this is not the best way to do it, but it works :-)
Maybe I don't understand what you are wanting, but I have dissabled a tab bar button by going into interface builder, then selecting the tab button i want to work on (small blue highlight color only on the place holder for the picture, the small box with a ? on it) then -> Tools Menu -> Inspector -> Tab Bar Item Properties (first tab on left in the Inspector) -> then a small radio button on the bottom says "Enabled" -> deselect this. Works for me, as I use this as a simple load screen on the first tab. Hope that helps.
Kirk
Related
The structure of my MainStoryboard is:
->Tab Bar Controller -> Navigation Controller -> View Controller (Search)
The behaviour I want to have is that when the user re-selects the Search tab, the UIScrollView on it scrolls to the top. I am unsure how to get the event from the TabBarController, however.
I've been looking at a lot of stuff about UITabBarDelegate, particularly:
- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item
I have, not quite managed to get this to work properly though. I am very unsure about how to go about setting the delegate (assuming that is the way it's done). I've tried hooking it up in IB, but it wouldn't let me. I also tried to get the UITabBar from the AppDelegate (after looking at some seemingly-related answers).
Any pointers will be greatly appreciated (unless they're null).
UITabBar *aTabBar = [UITabBarItem alloc] init];
....Any other modifications you want to make to aTabBar....
[aTabBar setDelegate:self]
Don't forget to add "<UITabBarDelegate>" to the "#interface" part of whatever object you're trying to designate as the delegate.
For my own code, I usually use some object that isn't the application delegate (as the app delegate is usually meant for application level events like "application is suspending" or "application is coming back into foreground"). If you add "<UITabBarDelegate>" to your Search view controller, make sure that whatever you do with the "didSelectItem" method is applicable only to the Search view controller. Otherwise instantiate some different object if you want to do actions on various view controllers based on which tab bar item is being displayed.
i have a viewcontroller with a button that when touched take us to a tabbarcontroller by modal (i'm using storyboard), this tabbar controller have 5 items, each taking to a different viewcontroller, but when i click that button it takes me to the first viewcontroller(from item1), can i change it without changing the items order on the tabbar? I want it to go to item 2...
I think i wasn't clear enough, i really don't know how to explain it, but hope you can understand!
i'm not using any code to do that, only storyboard!
I'm not sure how to do this with a storyboard, but normally you would just do this before you bring up your tab bar controller:
[myTabBarController setSelectedIndex:1];
or
[myTabBarController setSelectedViewController:mySecondViewController];
I just finished designing a application that uses a top bar that toggles between three UIViewControllers. My first thought was to use a UITabBarController, since it works very simular.
However, the tabBar is at the bottom and in my PSD, it's at the top. Is there anyway I can change it? I see in the library I can drag in a UITabBar, but I don't know how to get it to change pages from there.
Please help!
Coulton
Hope the below code helps
UITabBarController *tabC = [[UITabBarController alloc]init];
tabC.tabBar.frame = CGRectMake(0, 0, 320, 70);
NSArray *arr = [[NSArray alloc]initWithObjects:firstObj,secObj, nil];
tabC.viewControllers = arr;
[self.window addSubview:tabC.view];
Worked fine for me
I think it can be done, but you should be aware of this:
"Important: In iPhone OS 3.0 and later, you should not attempt to use the methods and properties of this class to modify the tab bar when it is associated with a tab bar controller object. Modifying the tab bar in this way results in the throwing of an exception. Instead, any modifications to the tab bar or its items should occur through the tab bar controller interface. You may still directly modify a tab bar object that is not associated with a tab bar controller."
So, in your UI (I suppose you defined it in Interface Builder), instantiate a UITabBar object (by choosing it in the IB library and dragging it to your view in IB). Choose the default position and also define the way that this tab bar autoresizes (using the size pane of the info window). Then, add an outlet to your view controller of type UITabBar, and, finally, connect the tab bar object to the tab bar outlet.
Once you have done this, in your view controller's viewDidLoad method you can customize any property of the tab bar that you want to.
I'm running into a problem with an iPad app where I would like to have UINavigationControllers in both of the views within a UISplitView. I've looked through other similar questions here, but most link to a tutorial online that doesn't completely solve the problem. Here's a 2-minute walkthrough to re-create the problem I'm having:
Create a New Project in XCode, starting from the Split View-based Application template.
Add the following NSLog statement as the first line within the DetailViewController's willHideViewController method:
NSLog(#"toolbar: %#", toolbar);
If you run the application now, the log will show that the DetailViewController's toolbar is alive and well. Now...
Open MainWindow.xib and expand the SplitViewController.
Drag a Navigation Controller from the library on top of the DetailViewController.
Expand the new Navigation Controller and change the class of the UIViewController within to a DetailViewController.
Ctrl-drag from the SplitViewController to the DetailViewController and assign it as the delegate.
Save MainWindow.xib and run the app again.
At this point, the detail view has a navigation bar and an empty toolbar. If you view the logs, you should find that the toolbar is null. Why is this? Am I missing some sort of connection in Interface Builder? Is the navigation bar the problem for some reason?
Unlike the tutorial at http://www.cimgf.com/2010/05/24/fixing-the-uisplitviewcontroller-template/, I would like to keep both the navigation bar and the toolbar (preferably with the toolbar at the top when in portrait and not visible when in landscape), so that I still have a functional "Back" button when the iPad is in portrait orientation.
Does anyone have any suggestions for fixing this problem? An example project with this sort of set-up would be ideal.
You can certainly use a navigation controller on the detail view of a split view controller. In fact, the iPad Settings app uses this approach. Probably the best way to get this setup is to create a new project in Xcode 4.x and select the "Master-Detail Application" template. It will generate a split view controller with 2 navigation controllers, one for the left view and one for the right view.
To your toolbar question, to keep things simple I would put a toolbar in the bottom. You can still put bar button items on the top navigation bar, although you can only put them in the left, middle, or right. If you need lots of items on the top bar, one way is to add a toolbar to the detail view and hide the navigation bar in the viewWillAppear event of the detail view class.
Here is an example on how to hide the navigation bar and show the toolbar:
- (void) viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
self.navigationController.toolbarHidden = NO;
self.navigationController.navigationBarHidden = YES;
}
I've found the built-in UISplitViewController to behave badly when trying to combine it with most of the other built-in view controller subclasses. Matt Gemmell's MGSplitViewController is a lot more flexible and has worked pretty well for me, despite the odd glitches (though those are at least fixable as the source code is provided).
In iPhone OS 3.0, you can set the toolbar items of a UINavigationController using the setToolbarItems:animated: method. However, this requires you pass in an array of UIToolbarItems. While I could programmatically create these toolbar items, I'd rather create them in Interface Builder if possible.
With this in mind, I have created a UIToolbar in "MyGreatViewController.xib" and have populated it with the wanted toolbar items. Then, in "MyGreatViewController.m", I get the items from the toolbar and pass them to setToolbarItems:animated::
- (void)viewDidLoad {
[super viewDidLoad];
[self setToolbarItems: [toolbar items]];
}
...where toolbar is an IBOutlet referring to the UIToolbar.
Is this a good approach? Is there a better way to accomplish this? Should I just create the items programmatically?
I don't know if this is documented anywhere, but I've found that in Interface Builder, if you enable the navigation controller's toolbar, you can drag bar items to your view controller, and they will automagically show up in the navigation controller's toolbar.
For example, here's what we can do (using Xcode 3.2 on Snow Leopard):
File->New Project.... Choose Navigation-based Application and create the project.
Open MainWindow.xib in Interface Builder.
Select the Navigation Controller, and in the Attributes inspector, check the "Shows Toolbar" box. This will cause a Toolbar object to appear.
Drag a Bar Button Item from the Library to the toolbar. It will appear in the toolbar. If you check the hierarchy in the NIB, you'll see that this new item is a child of the RootViewController.
It seems that any Bar Button Items added as children of the navigation item will show up in the navigation bar, and any Bar Button Items added as children of the view controller will show up in the toolbar.
(I stumbled on this by accident. If anyone can find documentation for this behavior, or any additional info, I'd like to hear about it.)
It's a perfectly acceptable way of doing it, but do bear in mind that loading xib files is quite expensive on the iPhone, and it may well be faster to create the toolbar items programatically in your viewDidLoad method.