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POstart playing audio from a background task via AVAudioPlayer in XCode
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copied!<p>I am trying to start playing a sound from a background task via an AVAudioPlayer that is instantiated then, so here's what I've got.</p> <p>For readability I cut out all user selected values.</p> <pre><code>- (void)restartHandler { bg = 0; bg = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{ [[UIApplication sharedApplication] endBackgroundTask:bg]; }]; tim = [NSTimer timerWithTimeInterval:.1 target:self selector:@selector(upd) userInfo:nil repeats:YES]; [[NSRunLoop currentRunLoop] addTimer:tim forMode:NSRunLoopCommonModes]; } - (void)upd { if ([[NSDate date] timeIntervalSinceDate:startDate] >= difference) { [self playSoundFile]; [tim invalidate]; [[UIApplication sharedApplication] endBackgroundTask:bg]; } } - (void)playSoundFile { NSError *sessionError = nil; [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:&sessionError]; // new player object _player = [[AVQueuePlayer alloc] init]; [_player insertItem:[AVPlayerItem playerItemWithURL:[[NSBundle mainBundle] URLForResource:@"Manamana" withExtension:@"m4a"]] afterItem:nil]; [_player setVolume:.7]; [_player play]; NSLog(@"Testing"); } </code></pre> <p>Explanation: <code>bg</code>, <code>tim</code>, <code>startDate</code>, <code>difference</code> and <code>_player</code> are globally declared variables. I call <code>- (void)restartHandler</code> from a user-fired method and inside it start a 10Hz repeating timer for <code>- (void)upd</code>. When a pre-set difference is reached, <code>- (void)playSoundFile</code> gets called and initiates and starts the player. The testing NSLog at the end of the method gets called.</p> <p>Now the strange thing is if I call <code>- (void)playSoundFile</code> when the app is active, everything works out just fine, but if I start it from the background task it just won't play any sound.</p> <p>Any help, hint, solution or heads up is greatly appreciated. </p> <p><strong>Edit</strong></p> <p>So I tried using different threads at runtime and as it seems, if the Player is not instantiated on the Main Thread this same problem will appear. I also tried using <code>AVPlayer</code> and <code>AVAudioPlayer</code> where the <code>AVAudioPlayer</code>'s <code>.playing</code> property did return YES and still no sound was playing.</p>

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