Using Xcode 6 I have created an Tabbed Application using a storyboard with the supplied template.
I need a function to fire when the third tab of the UITabBarController is selected.
I can’t use the ViewDidLoad as I need it fire every time the view is accessed by clicking on the tab (not just the first time( and I can't use ViewWillAppear as I need specific behaviour when view is accessed via the tab as opposed to segued back to from subsequent (modal) view controllers.
Any advice would be appreciated. Many thanks in advance.
Implement this delegate method of UITabBarControllerDelegate on some UIViewController class
- (void)tabBarController:(UITabBarController *)theTabBarController didSelectViewController:(UIViewController *)viewController {
NSUInteger indexOfTab = [theTabBarController.viewControllers indexOfObject:viewController];
// Your code here
}
OR
You can subclass UITabBarController and override the following method.
- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item {
NSUInteger indexOfTab = [[theTabBar items] indexOfObject:item];
// Your code here}
Related
I have a NavigationController then a TabBarController which has Four Tabs.
I wanted to display Different titles on TopBar when a Different Tab is selected.
One way was to Embed each TabBarItem View into Navigation Controller but for some reason this doesn't seems the correct way, i wanted to apply this via code.
I managed accomplish this by using this code: (Products_ViewController.m custom class)
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view.
UINavigationController *navCon = (UINavigationController*) [self.navigationController.viewControllers objectAtIndex:0];
navCon.navigationItem.title = #"Products";
}
But the problem is now when a tab is clicked First time, it changes the title but then it doesn't. I then applied the same code on -(void)viewDidAppear{} but still the same result.
How can i manage to display navigation top bar title (or run the above code) whenever the tab bar item is clicked or the view is shown?
Thanks!
You could implement the UITabBarControllerDelegate in the Products_ViewController.m class and execute your code in the tabBarController:didSelectViewController: method.
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController {
UINavigationController *navCon = (UINavigationController*) [self.navigationController.viewControllers objectAtIndex:0];
navCon.navigationItem.title = #"Products";
}
In the viewDidLoad method you have to set the delegate to self.
I need to intercept a UITabBar tap precisely so I can conditionally abort moving to the intended ViewController (i.e. conditionally dismiss the tap).
I create my UITabBar in the storyboard. The UITabBar is the root view of my entire app. One of the tabBar items is a profile page (so to speak). If a user does not yet have an account, I want to ignore their clicking on that specific tabBar item. The behavior I seek is that the user will not leave the present ViewController they are in to go to the Tab selected. But instead, I want them to segue to the registration page. Any ideas how I might do this interception?
UPDATE
I have managed to add the following method in my AppDelegate. The method is called, but the transition is not intercepted. How do I intercept and abort the transition?
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
{
NSLog(#"Intercept tabBarController in app delegate tap gesture but then do nothing");
}
The NSLog line is printed, but transition still occurs.
Sounds like you are on the right path. But you should use
- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController
If you need more help, let me know.
You need to go with the UITabBar delegate of tabBar:didSelectItem:
Ex:
- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item {
// Use the item to do further
}
Hi I am developing a UITabBar application.
I need:
1.When I select a TabBAr item I need to get the current selected index.
2.Based on the current index I want to perform some action in AppDelegate.
3.So is there a any delegate methods which called whenever I pressed the tab bar items.
4.Please suggest some way to check in AppDelegate every time I presses Tab Items
Thank You.
After a quick google:
- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item
Make sure to link the delegate in IB...
Yes you can using this delegate method
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController {
NSLog(#"selected index : %i",[tabBarController selectedIndex]);
}
this method called whenever you touch any of TabBarItem.
First set the delegate Protocol e.g UITabBarControllerDelegate and then
put self.tabbarcontroller.delegate = self; in your ViewDidLoad or somewhere where the object get's initialized
I have 2 view controllers and a tab bar controller created in storyboard.
is it possible to execute a method in either of the 2 view controllers when the relevant tab bar is pressed?
Ive tried several ways but they need a nib name on the firstViewController or secondViewController if I want to initialize an object of the firstViewController, normally the firstViewController is just created on launch,
Any help would be appreciated, I'm vaguely familiar with the uitabcontroller app delegate but I don't know how to hook up the two view controllers to the tab controller
Have a look at the UITabViewController Delegate :
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.
Reference : http://developer.apple.com/library/ios/#DOCUMENTATION/UIKit/Reference/UITabBarControllerDelegate_Protocol/Reference/Reference.html
What you need should be achievable by implementing :
- (void)tabBarController:(UITabBarController *)tabBarController
didSelectViewController:(UIViewController *)viewController
If you are using storyboard, do this
in didFinishLaunchingWithOptions
UITabBarController *tabBar = (UITabBarController *)self.window.rootViewController;
[tabBar setDelegate:self];
And then
-(void) tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
{
//Write your code here
}
I got TabBar Application with 3 ViewControllers.
Can i know from the ViewControllers's method which ViewContoller was desplayed before (1 or 2)? Or maybe i open VeiwController from some other .xib
You can do this by implementing UITabBarController delegate method -
- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController
{
}
in this you can check for [tabBarController selectedViewController] , here selectedViewController is the view controller which is currently selected and viewController is which is going to be selected.
I just creating #property in target VeiwController and set this #property firstly in viewDidLoad. So i know that firstly this ViewController will appear from TabBar. After that i can change it in some other ViewController's methods, which call some subviews (.xib).