Update UIProgressView based on how much of an mp3 has played - ios

Question

I've been searching for a simple way to show the progress of playing an MP3 in a UIProgressView. I have a feeling it's going to involve an NSTimer object but I'm not sure how to implement it.
Here's what I have so far.
#import "ViewController.h"
#interface ViewController ()
#property (weak, nonatomic) IBOutlet UISlider *VolumeLevel;
#property (weak, nonatomic) IBOutlet UIProgressView *progressBar;
#end
#implementation ViewController
AVAudioPlayer *player;
- (IBAction)play:(id)sender {
[player play];
}
- (IBAction)pause:(id)sender {
[player stop];
}
- (IBAction)volume:(id)sender {
player.volume = _VolumeLevel.value;
}
- (void)viewDidLoad
{
[super viewDidLoad];
NSURL *songURL =[NSURL fileURLWithPath:[[NSBundle mainBundle]pathForResource:#"Gregory Is Here" ofType:#"mp3"]];
player =[[AVAudioPlayer alloc]initWithContentsOfURL:songURL error:nil];
player.volume = 0.5;
// Do any additional setup after loading the view, typically from a nib.
}

Answer 1

Using a NSTImer, you can do :
- (IBAction)play:(id)sender {
[player play];
myTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:#selector(updateProgressBar) userInfo:nil repeats:YES];
}
- (IBAction)pause:(id)sender {
[player stop];
[myTimer invalidate];
}
- (void)updateProgressBar {
float progress = player.currentTime / player.duration;
[myProgressBar setProgress:progress animated:YES];
}
You can change the timer timeInterval parameter to update the progress bar more or less frequently (1.0 is for 1 second).

Answer 2

-(void) setPlayProgress
{
if (player.isPlaying) {
slider.value=abs(player.currentTime);
NSString *duration=[self getTimeStrFromInterval:player.duration-player.currentTime];
lblDuration.text=duration;
}
[self performSelector:#selector(setPlayProgress) withObject:nil afterDelay:0.1];
}
// Show time
-(NSString *) getTimeStrFromInterval:(NSInteger) timeSinceStart{
int seconds = timeSinceStart;
int minutes = seconds/60;
int hours = minutes/60;
minutes = minutes%60;
seconds = seconds%60;
NSString *strHours;
NSString *strMinutes;
NSString *strSeconds;
strHours = [NSString stringWithFormat:#"%d",hours];
strMinutes = [NSString stringWithFormat:#"%d",minutes];
strSeconds = [NSString stringWithFormat:#"%d",seconds];
if (hours<10) {
strHours = [NSString stringWithFormat:#"0%d",hours];
}
if (minutes<10) {
strMinutes = [NSString stringWithFormat:#"0%d",minutes];
}
if (seconds<10) {
strSeconds = [NSString stringWithFormat:#"0%d",seconds];
}
NSString* intervalString;
if ([strHours intValue]>0) {
intervalString = [NSString stringWithFormat:#"%#:%#:%#",strHours,strMinutes,strSeconds];
}
else{
intervalString = [NSString stringWithFormat:#"%#:%#",strMinutes,strSeconds];
}
return intervalString;
}