Question

I’ve got an application with a navigation tree. Somewhere there is an audio player with an mp3.

UITabViewController // controlled by AppDelegate.m
    -> UINavigationController
        -> UITableViewController // controlled by TableViewController.m
            -> UIViewController // with my AVAudioPlayer controlled by AudioViewController.m

In AudioViewController.m I have all my audio engine so i play/pause/stop it, and even kill it when pressing back button (using viewWillDisappear etc) – it plays only in this one view, not another, and it’s good.

However there is an issue when i press home button while playback is on. It stops, but after going back to my app, it plays again from remembered time stamp.

I tried all this:

- (void)viewDidUnload
{
    [super viewDidUnload];
    [self audioStop:self];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [self audioStop:self];
    [super viewWillDisappear:animated];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    [self audioStop:self];
}

- (void)viewWillUnload
{
    [self audioStop:self];
    [super viewWillUnload];
}

- (void)awakeFromNib
{
    [super awakeFromNib];
    [self audioStop:self];
}

But nothing happens.

Now i know that to manage if home button was pressed, i need to use applicationWillResignActive method from AppDelegate, but i have totally no idea how do i stop my audioplayer from here. I’m quite new to iOS and i’m not familiar with how delegates work, so please help me work this out.

Answer 1

Let you AppDelegate hold a reference for you UIViewcontroller some how and call it. Make sense?

   AppDelegate
        |
        v
    TableViewController (@property)
        |
        v
    UIViewController (@property)
        |
        v
    AudioPlayer (@property) --> [ stop];

Edit:

@interface TableViewController : UIViewController
{
     AudioPlayer * audioPlayer;
}
@property(nonatomic, retain) AudioPlayer * audioPlayer;
... // other stuff
@end

@implementation TableViewController
@synthesize audioPlayer;
... // other stuff
@end

This way you can access the audio player from TableViewController object. If you hold TableViewController object this way it should be easy for you.

[tableViewController.audioPlayer someMethod]; 

something like that ..