UITabBar app and button that plays music in a tab - iphone

Question

I have an instance of AVAudioPlayer running inside one of my tabs. It is activated through an IBAction.
I would like the music to stop when a user clicks on another tab.
How would I go about doing this?
I've tried theAudio.stop; in viewDidLoad, but that didn't work.

Answer 1

In your UITabBarControllerDelegate implement the following method;
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
This is called whenever the user selects a new view in the controller.
I think you could also override the following method in the UIViewController that's playing the audio
-(void) viewDidDisappear:(BOOL)animated

Answer 2

Wire up a UITabBarControllerDelegate to your main view, then listen for (void)tabBarController:(UITabBarController *)tabBarController didSelectItem:(UITabBarItem *)item
When you get that event, find the player in your object model and stop it.

Answer 3

I happened upon this post while trying to answer the same exact question. Just in case anyone else is still looking, I finally figured out how to do it with an NSNotificationCenter. Basically, an NSNotificationCenter sends "broadcasts" a message to the entire application. If an "observer" happens to be listening, as you can see below, a given method is called. The code looks like this:
In your App Delegate:
- (void)applicationDidFinishLaunching:(UIApplication *)application {
// Add the tab bar controller's current view as a subview of the window
[window addSubview:tabBarController.view];
// Make sure you add this so that your tab bar calls its delegate methods
tabBarController.delegate = self;
}
// Optional UITabBarControllerDelegate method (this will be commented out by default - uncomment it)
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController {
// Create the NSNotificationCenter
[[NSNotificationCenter defaultCenter] postNotificationName:#"tabChanged" object:nil];
}
In your view controller:
- (void)viewDidLoad {
[super viewDidLoad];
// Register an observer to stop audio recording/playing on tab change
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(tabChanged)
name:#"tabChanged"
object:nil];
}
- (void)tabChanged {
#"Received Notification!";
if([player isPlaying]) {
[player stop];
}
}