update UISlider progress bar currenttime and duration when audio plays - iphone

Question

Have a UISlider ProgressBar on UIToolbar when audio plays wants UISlider ProgressBar to display the duration of the audio file and currenttime of the audio file.
- (void)playAction:(id)sender
{
if([player isPlaying])
{
[sender setImage:[UIImage imageNamed:#"1play.png"] forState:UIControlStateSelected];
[player pause];
//[self pauseTimer];
}else{
[sender setImage:[UIImage imageNamed:#"audiopause.png"] forState:UIControlStateNormal];
[player play];
//[self resumeTimer];
}
[self updateProgressBar:timer];
}
- (void)updateProgressBar:(NSTimer *)timer
{
NSTimeInterval playTime = [self.player currentTime];
NSTimeInterval duration = [self.player duration];
float progress = playTime/duration;
[_progressBar setProgress:progress];
}
But it is not working.
Thanks for help.

Answer 1

You're probably going to want to call the updateProgressBar method using a timer, rather than what you're doing right now (calling it in the playAction method). Instead, you can use the playAction method to create the timer that calls updateProgressBar, or pause/stop existing timers.
Looks like you already have an instance variable to keep track of the timer, which is good. Here is how you would create a new timer:
[timer invalidate]; // stop the old timer
// this timer runs once per second, perhaps you want to make it something shorter which would look less choppy
NSTimer *progressTimer = [NSTimer timerWithTimeInterval:1.0 target:self selector:#selector(updateProgressBar:) userInfo:nil repeats:YES];
[[NSRunLoop mainRunLoop] addTimer:progressTimer forMode:NSRunLoopCommonModes];
timer = progressTimer;
If you have a method to pause the audio, you can invalidate the timer there too.
[timer invalidate];
timer = nil;
Altogether, in your code, this would look something like:
- (void)playAction:(id)sender
{
if([player isPlaying])
{
[sender setImage:[UIImage imageNamed:#"1play.png"] forState:UIControlStateSelected];
[player pause];
[timer invalidate];
timer = nil;
} else {
[sender setImage:[UIImage imageNamed:#"audiopause.png"] forState:UIControlStateNormal];
[player play];
[timer invalidate];
NSTimer *progressTimer = [NSTimer timerWithTimeInterval:1.0 target:self selector:#selector(updateProgressBar:) userInfo:nil repeats:YES];
[[NSRunLoop mainRunLoop] addTimer:progressTimer forMode:NSRunLoopCommonModes];
timer = progressTimer;
}
}
- (void)updateProgressBar:(NSTimer *)timer
{
NSTimeInterval playTime = [self.player currentTime];
NSTimeInterval duration = [self.player duration];
float progress = playTime/duration;
[_progressBar setProgress:progress];
}

Answer 2

Try this:
This is for the update slider..
[NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:#selector(updateSlider) userInfo:nil repeats:YES];
slider.maximumValue = avAudioPlayer.duration;
[slider addTarget:self action:#selector(sliderChanged:) forControlEvents:UIControlEventValueChanged];
- (void)updateSlider {
slider.value = avAudioPlayer.currentTime;
}
- (IBAction)sliderChanged:(UISlider *)sender {
[avAudioPlayer stop];
[avAudioPlayer setCurrentTime:slider.value];
[avAudioPlayer prepareToPlay];
[avAudioPlayer play];
}