didSelectViewController is not being fired when selectedIndex is set programmatically on UITabBarController object, when tapping manually everything works fine.
From my current work, it seems selectedIndex is updated only if the tabbed view hasn't been loaded before - perhaps the same applies to the responder chain "the other way around".
You might have more luck by switching tabs using selectedItem, at least I can identify the correct tab in the viewWillAppear in a tab's viewcontroller using the Item, but not the Index.
For you, the most obvious "fix" would be to also invoke didSelectViewController in every piece of code that changes the Index.
Related
(Apologies for not being able to embed my images yet).
Using iOS storyboards, I have a UITabBarController with a UINavigation Controller/UITableView(1) embedded in it. This UITableView(1) then calls another UITableView(2):
What I'm trying to do is to make UITableView(2) appear when the Tab Bar is changed to that tab, and then have the UINavigationBar left arrow button exist to get back to UITableView(1).
The existing functionality I can think of which does this is the iPhone Mail app, where when you launch it you see your Inbox, and you can hit the left-arrow Mailboxes button to get back to your mail box list.
I've tried attaching the tab bar directly to UITableView(2) but it doesn't work as expected, there's no left arrow back button to get back to the previous view when the app is run.
I've also tried adding a navigation controller to that UITableView(2) and the Navigation controller correctly appears, but still without any back button:
Any suggestions as to what I'm doing wrong would be greatly appreciated, I'm fairly new with storyboards and it's difficult to find what to search to get this working.
If it's not possible with just storyboards themselves, is there some kind of automatic (non-visible) push to the 2nd UITableView I could do?
Thanks!
Nick.
This tutorial will definitely help you : http://maybelost.com/2011/10/tutorial-storyboard-in-xcode-4-2-with-navigation-controller-and-tabbar-controller-part1/
I ended up implementing it the following way, as I wanted to perform the majority of the work within storyboards.
I set up the storyboard with the tab bar embedding the UINavigationController, which contained UITableView(1) which then contained a custom segue to UITableView(2):
Then within the class associated with UITableView(1) I added this single line:
- (void)viewDidLoad {
[self performSegueWithIdentifier:#"campaigns" sender:self];
...
}
On load of the tab, the viewDidLoad of UITableView(1) instantly calls UITableView(2) without any kind of animation, showing the back button to UITableView(1), which is exactly what I wanted.
Thanks to those who responded!
You can implement the delegate method as below.
(void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
In this method you can check for the tabBarController.selectedIndex or viewController object. This ensures the selection of correct tab , then push the controller having table 1, then push the controller having table 2.
New to iOS, kindly bare if the question is very basic? When I press the tab button multiple times, it is not invoking viewWillAppear function? If I am wrong, then which function gets invoked, each time a tab button is pressed being on the same tabview?
You are correct, viewWillAppear is a little special, it is usually called automatically but in some cases including when you are adding a view controllers view manually (view addSubview:), and also when adding this as a view controller to a UITabViewController it doesn't get messaged.
This however is only for the root view, as you navigate (maybe with a navigation controller) back and forth, that root view's viewWillAppear will get triggered as some point.
In short, if you need to implement something in viewWillAppear in these cases, you should message it yourself when you know it's going to be presented. You can handle this case in your view controller, check out the following article about the matter:
http://www.touchthatfruit.com/viewwillappear-and-viewdidappear-not-being-ca
Good luck.
In the view controller that has a UITabBarItem, i realized that viewDidLoad() method only gets called the first time when the tab bar item is clicked. So I dont know how to bring up the dynamic graphics when it's clicked the 2nd time. Can some guru help me on this? thanks in advance.
Should I conform to some kind of delegates or should i do it within didSelectViewController method on the root controller of all the tab bars? If i do the later one, it just seems to be weird since i think the controller that has the corresponding tab bar item should render itself instead of doing the rendering on root controller..
You want to put any code that should run every time the view controller appears in viewWillAppear: instead of viewDidLoad. viewDidLoad is designed for code that should run when the view backed by your UIViewController is created (and then possibly re-created after being thrown away during low-memory situations).
Actually i resolved this by using the parameter passed into the callback didSelectViewController(param).
I have a tab bar interface with three tabs. I would like them to animate when I switch between them. I implemented didSelectViewController (and all the associated delegate stuff) which is called when I press the tabs but not when I switch tabs programmatically. The docs say as much,
"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."
Anyone know any workarounds?
Thanks! - Jon
Well, if you are switching them programmatically why can't you create proper animation yourself? I mean you do know which tab gets selected, right?
you can call the method when you switch them programmatically yourself. or write another method to do your animation and call IT whenever you switch tabs programatically
I've got a UITabBarController in my project that I'm creating programmatically - without a nib. I create the view controllers, initialize them, and then create an array of them and use the setViewControllers:animated: method on my tab bar controller. This works except that when it appears, my tab bar controller doesn't have anything selected. If I call [ tabBarController setSelectedIndex:1 ], then it works just fine, but if I call [ tabBarController setSelectedIndex:0 ], nothing is selected. Is this a weird bug or am I doing it wrong? This is using the iPhone SDK 3.0.
Show your code if you will, will make it easier for us to find the problem...But from not seeing anything, what I would think is wrong is that when you initialize your UITabBarButtons you are not giving any of them an index of 0...
It turns out that the code was written by me a long time ago, when I did stupid things like override the -tabBarItem accessor method in the UIViewController. Moving the tab bar item customization to -initWithStyle: fixed this problem.
This happened for me when I set the UIViewController's tabBarItem property in viewDidLoad instead of its init method.