Question

I’m trying to add a UIButton to UITabBar in my iPad application with following code:

TabBarAppDelegate *delegate = (TabBarAppDelegate *)[[UIApplication sharedApplication] delegate];
UITabBarController *tabbar = (UITabBarController *)delegate.window.rootViewController;

UIButton *b = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 20, 20)];
[tabbar.view addSubview:b];

tabbar is OK and referencing to a correct tabbar item (say, I can switch active tab with following code: [tabbar setSelectedIndex:1];).

This code is called by some other custom button. Though there are no errors in the log, the button doesn’t show on the tabbar 🙁

What am I doing wrong and what is a right way to add UIButton to UITabBar? 🙂 Here is an example:

http://gyazo.com/99fc0df0ed47dd6be91b558161cab4f9.png

Thanks in advance!

Edit: OK, if I’ll stick to UIToolbar option, then what is a right way to switch between views? Create an NSArray of ViewContollers and load corresponding ViewController’s view to an active View?

Answer 1

You cannot add a UIButton directly to a UITabBarController. From the UITabBarController Class Reference:

You should never access the tab bar view of a tab bar controller
directly.

Further along, the documentation reads:

Tab bar items are configured through their corresponding view
controller. To associate a tab bar item with a view controller, create
a new instance of the UITabBarItem class, configure it appropriately
for the view controller, and assign it to the view controller’s
tabBarItem property. If you do not provide a custom tab bar item for
your view controller, the view controller creates a default item
containing no image and the text from the view controller’s title
property.

Therefore your two options are:

1. Create a UITabBarItem (documentation) and add that.
2. Use a UIToolBar instead, but remember to add UIBarButtonItems.