AVPlayer volume control with slider and iphone buttons

Question

I have a radio streaming AVPlayer and I created a slider which controls the volume for the player.

-(void)adjustVolume
{
    if (self.player != nil)
    {
        NSLog(@"Adjusting volume...");
        self.player.volume = volumeControl.value;
         NSLog(@"%f",self.player.volume);
    }
}

I need to connect the value from the slider to the values I have when pushing the volume buttons. So for example if I move the slider to 50% and after that I push the volume up button on the side of the phone, I need it to increase from 50%, as that was the volume I've set through the slider.

How can I do this?

LATER EDIT:

With this code I managed to update the slider as i press the volume keys, but I can't drag the slider anymore since it always updates with the system volume.

audioSession = [AVAudioSession sharedInstance];
BOOL ok;
NSError *setCategoryError = nil;
ok = [audioSession setCategory:AVAudioSessionCategoryPlayback error:&setCategoryError];

volume = audioSession.outputVolume;
volumeControl.value = volume;
NSTimer *volumeTimer = [NSTimer scheduledTimerWithTimeInterval:0.01 target:self selector:@selector(updateSound) userInfo:nil repeats:YES];

and the updateSound:

- (void)updateSound{
    volume = audioSession.outputVolume;
    volumeControl.value = volume;
}

How can i change the system volume when I move the slider? I tried to give a value to audioSession.outputVolume but of course, it doesn't work that way.

Answer 1

You can listen to volume change notificaions

[[NSNotificationCenter defaultCenter]
 addObserver:self
 selector:@selector(volumeChanged:)
 name:@"AVSystemController_SystemVolumeDidChangeNotification"
 object:nil];

And your selector would look like this

- (void)volumeChanged:(NSNotification *)notification
{
    float volume =
    [[[notification userInfo]
      objectForKey:@"AVSystemController_AudioVolumeNotificationParameter"]
     floatValue];

    // Do stuff with volume
}

Answer 2

Finally found the solution to what I was trying to do here

I removed all above code and included MediaPlayer framework in my .h file and this code in my .m file:

   UIView *wrapperView = [[UIView alloc] initWithFrame:CGRectMake(30, 350, 260, 20)];
    wrapperView.backgroundColor = [UIColor clearColor];
    [self.view addSubview:wrapperView];

    MPVolumeView *volumeView = [[MPVolumeView alloc] initWithFrame: wrapperView.bounds];
    [wrapperView addSubview:volumeView];

Hope this helps someone else as well.