Multiple audio files playing at once in iOS App - ios

Question

I have an iOS app which works like this:
First view
3 buttons that link to different views, each has its own audio file within
Imagine user opens one view, and starts to play the audio file. When they navigate around the app, the audio file still plays which is fine, Im happy with that.
However, if user then opens the second audio file and presses play, it plays on top of the first one so 2 audios are playing together.
How do I tell the code that if another play button is pressed it should stop the first audio file that is playing??
I am using AVFoundation framework to do this
Code is as follows:
NSString *stringPath = [[NSBundle mainBundle]pathForResource:#"01" ofType:#"MP3"];
NSURL *url = [NSURL fileURLWithPath:stringPath];
NSError *error;
avPlayer = [[AVAudioPlayer alloc]initWithContentsOfURL:url error:&error];
[avPlayer setNumberOfLoops:2];
[avPlayer setVolume:self.sliderVolumeOutlet.value];
[NSTimer scheduledTimerWithTimeInterval:.1 target:self selector:#selector(updateMyProgress) userInfo:nil repeats:YES];
-(void)updateMyProgress
{
float progress = [avPlayer currentTime]/[avPlayer duration];
self.myProgressView.progress = progress;
}
- (IBAction)sliderVolumeAction:(id)sender {
UISlider *mySlider = sender;
[avPlayer setVolume:mySlider.value];
}
- (IBAction)stopButton:(id)sender {
[avPlayer stop];
[avPlayer setCurrentTime:0];
}
- (IBAction)pauseButton:(id)sender {
[avPlayer pause];
}
- (IBAction)playButton:(id)sender {
[avPlayer play];
}
- (IBAction)backButtonEvent:(id)sender {
[self dismissViewControllerAnimated:YES completion:NULL];
}

Answer 1

You can check whether it is playing the previous track or not by if ([AVPlayer rate] != 0.0)
If it is playing then you can either add the next track into queue or just use this function to replace current track with the new one - (void)replaceCurrentItemWithPlayerItem:(AVPlayerItem *)item

Answer 2

Perhaps creating some sort of playSound function would be better suited for this. Something like this:
- (void)playSoundWithFileName:(NSString *)fileName andExtension:(NSString *)extension {
NSString *stringPath = [[NSBundle mainBundle]pathForResource:fileName ofType:extension];
NSURL *url = [NSURL fileURLWithPath:stringPath];
NSError *error;
if (avPlayer) {
[avPlayer stop];
avPlayer = nil;
}
avPlayer = [[AVAudioPlayer alloc]initWithContentsOfURL:url error:&error];
if (error)
NSLog(#"Error");
else {
[avPlayer setNumberOfLoops:2];
[avPlayer setVolume:self.sliderVolumeOutlet.value];
[avPlayer play];
}
}
Use:
[self playSoundWithFileName:#"01" andExtension:#"MP3"];
[NSTimer scheduledTimerWithTimeInterval:.1 target:self selector:#selector(updateMyProgress) userInfo:nil repeats:YES];
and call -(void)playSoundWithFileName whenever you want to play another sound.
Or if you were using the AVPlayer class:
- (void)playSoundWithFileName:(NSString *)fileName andExtension:(NSString *)extension {
NSString *stringPath = [[NSBundle mainBundle]pathForResource:fileName ofType:extension];
NSURL *url = [NSURL fileURLWithPath:stringPath];
AVPlayerItem *item = [AVPlayerItem playerItemWithURL:url];
if (avPlayer)
[avPlayer replaceCurrentItemWithPlayerItem:item];
else
avPlayer = [AVPlayer playerWithPlayerItem:item];
[avPlayer setVolume:self.sliderVolumeOutlet.value];
[avPlayer play];
}
Though the latter doesn't allow you set a number of loops.