Question

How this UIButton rewind can send notification to UIButton play to perform playpauseaction method when rewind button is clicked.

-(void)rewind:(id)sender{
[timer invalidate]; 
audioPlayer.currentTime = 0;
MainViewController *viewController = [[MainViewController alloc] init];
viewController.view.frame = CGRectMake(0, 0, 320, 480);
[self.view addSubview:viewController.view];
[self.view addSubview:toolbar];
[viewController release];
} 

 -(void)playpauseAction:(id)sender {    
if([audioPlayer isPlaying])
{
    [sender setImage:[UIImage imageNamed:@"Play Icon.png"] forState:UIControlStateSelected];
    [audioPlayer pause];
    [self pauseTimer];
    [self pauseLayer:self.view.layer];
}
else
{
    [sender setImage:[UIImage imageNamed:@"pause.png"] forState:UIControlStateNormal];
    [audioPlayer play];
    [self resumeTimer];
    [self resumeLayer:self.view.layer];

    if(isFirstTime == YES)
    {
        self.timer = [NSTimer scheduledTimerWithTimeInterval:11.0
                                                      target:self
                                                    selector:@selector(displayviewsAction:)
                                                    userInfo:nil
                                                     repeats:NO];
        isFirstTime = NO;
    }
    }
    }

rewind button when clicks perform rewind method and as well send notification to play button to perform playpauseAction method.

Thanks for help.

EDIT
Have declared

    @property (nonatomic, retain) UIButton *playButton;
    @synthesize playButton = _playButton; 
   [self playpauseAction:_playButton];

what happening is when clicking on rewind button it performing play pause action method but not toggling play button to pause as per playpauseaction method. why is that

Answer 1

If you have a reference to your play pause button (which you will want to have to make this kind of thing a ton easier), you can just write this line in your rewind method

[self playpauseAction:playpauseButton];

You don’t need to use the notification center at all