UITabBarControllerDelegate Protocol Reference
| Conforms to | |
| Framework | /System/Library/Frameworks/UIKit.framework |
| Availability | Available in iOS 2.0 and later. |
| Companion guide | |
| Declared in | UITabBarController.h |
Overview
You use the UITabBarControllerDelegate protocol when you want to augment the behavior of a tab bar. In particular, you can use it to determine whether specific tabs should be selected, to perform actions after a tab is selected, or to perform actions before or after the user customizes the order of the tabs. After implementing these methods in your custom object, you should then assign that object to the delegate property of the corresponding UITabBarController object.
All of the methods in this protocol are optional. For more information on how to use and configure tab bar controllers and their delegates, see View Controller Programming Guide for iOS.
Instance Methods
tabBarController:didEndCustomizingViewControllers:changed:
Tells the delegate that the tab bar customization sheet was dismissed.
Parameters
- tabBarController
The tab bar controller that is being customized.
- viewControllers
The view controllers of the tab bar controller. The arrangement of the controllers in the array represents the new display order within the tab bar.
- changed
A Boolean value indicating whether items changed on the tab bar.
YESif items changed orNOif they did not.
Discussion
You can use this method to respond to changes to the order of tabs in the tab bar.
Availability
- Available in iOS 2.0 and later.
Declared In
UITabBarController.htabBarController:didSelectViewController:
Tells the delegate that the user selected an item in the tab bar.
Parameters
- tabBarController
The tab bar controller containing viewController.
- viewController
The view controller that the user selected. In iOS v3.0 and later, this could be the same view controller that was already selected.
Discussion
In iOS v3.0 and later, the tab bar controller calls this method regardless of whether the selected view controller changed. In addition, it is called only in response to user taps in the tab bar and is not called when your code changes the tab bar contents programmatically.
In versions of iOS prior to version 3.0, this method is called only when the selected view controller actually changes. In other words, it is not called when the same view controller is selected. In addition, the method was called for both programmatic and user-initiated changes to the selected view controller.
Availability
- Available in iOS 2.0 and later.
Declared In
UITabBarController.htabBarController:shouldSelectViewController:
Asks the delegate whether the specified view controller should be made active.
Parameters
- tabBarController
The tab bar controller containing viewController.
- viewController
The view controller belonging to the tab that was tapped by the user.
Return Value
YES if the view controller’s tab should be selected or NO if the current tab should remain active.
Discussion
The tab bar controller calls this method in response to the user tapping a tab bar item. You can use this method to dynamically decide whether a given tab should be made the active tab.
Availability
- Available in iOS 3.0 and later.
Declared In
UITabBarController.htabBarController:willBeginCustomizingViewControllers:
Tells the delegate that the tab bar customization sheet is about to be displayed.
Parameters
- tabBarController
The tab bar controller that is being customized.
- viewControllers
The view controllers to be displayed in the customization sheet. This list typically contains all custom view controllers you added but does not include some standard controllers, such as the one that manages the More tab.
Availability
- Available in iOS 3.0 and later.
Declared In
UITabBarController.htabBarController:willEndCustomizingViewControllers:changed:
Tells the delegate that the tab bar customization sheet is about to be dismissed.
Parameters
- tabBarController
The tab bar controller that is being customized.
- viewControllers
The view controllers of the tab bar controller. The arrangement of the controllers in the array represents the new display order within the tab bar.
- changed
A Boolean value indicating whether items changed on the tab bar.
YESif items changed orNOif they did not.
Discussion
This method is called in response to the user tapping the Done button on the sheet but before the sheet is dismissed.
Availability
- Available in iOS 3.0 and later.
Declared In
UITabBarController.h© 2009 Apple Inc. All Rights Reserved. (Last updated: 2009-07-17)