How to play a sound file at maximum volume in iOS without a sound indicator change

Question

In my app I'm required to play a sound from a volume of 0 to maximum system volume (it's an alarm app).

I currently use AVAudioPlayer to play the sound and MPMusicPlayerController to maximize the device's volume for the duration of the alarm

MPMusicPlayerController.applicationMusicPlayer.volume = 1.0;


NSString *fileName = [NSString stringWithFormat:alarm.sound];
fileName = [fileName stringByDeletingPathExtension];

NSString *soundFilePath = [[NSBundle mainBundle] pathForResource:fileName ofType:@"aifc"];
NSURL *soundFileURL = [NSURL fileURLWithPath:soundFilePath];

audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:soundFileURL error:nil];
audioPlayer.volume = 0.0;
audioPlayer.numberOfLoops = -1;

[audioPlayer prepareToPlay];

audioPlayer.play;

and then I schedule a timer to increase the volume

timer = [NSTimer scheduledTimerWithTimeInterval:1.0
                                         target:self
                                       selector:@selector(pollTimeForGradualVolumeIncrease)
                                       userInfo:nil repeats:YES];

//Increase the volume gradually

- (void)pollTimeForGradualVolumeIncrease
{
    timerSecond += 1;

    if (audioPlayer.volume < 1.0 && timerSecond % 1 == 0)
    {
        [audioPlayer setVolume:audioPlayer.volume + 0.02];
        UISlider *slider = volumeSliderView.subviews[0];
        [slider setValue:1.0 animated:NO];
    }
    else if (audioPlayer.volume >= 1.0)
    {
        timerSecond = 0;
        timer.invalidate;
        timer = nil;
    }
}

The problem with this is that the iOS volume indicator will appear when setting MPMusicPlayerController.applicationMusicPlayer.volume

Is there a way to play a sound file at maximum device volume without the displaying the iOS volume changed indicator?

Answer 1

I was experimenting with related things 8 months ago, and as far as I remember, if an MPVolumeView is present, iOS then doesn't show the system volume changed indicator.

If you don't actually want to see the MPVolumeView, I suppose you could hide it behind another view.