How do i play many sounds selected by picker? - objective-c

Question

I want to make an app playing sound selected by picker.
When i select a file by picker, if i touch button, the sound will play.
But, it cannot.
I cannot point the miss of the code.
Anyone can help me to troubleshoot my code?
Here is my code for troubleshooting.
.H file
#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>
#interface ViewController : UIViewController <
UIPickerViewDelegate,UIPickerViewDataSource,AVAudioPlayerDelegate> {
NSArray *ap;
NSString *si;
UIButton * utab;
AVAudioPlayer *apr;
}
#property (weak, nonatomic) IBOutlet UILabel *ll;
#property (weak, nonatomic) IBOutlet UIImageView *igv;
#property (weak, nonatomic) IBOutlet UIPickerView *pv;
#property (weak, nonatomic) NSArray *msa;
#end
.M file
#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>
#interface ViewController ()
#property AVAudioPlayer *apr;
#end
#implementation ViewController
#synthesize ll,igv,pv;
- (void)viewDidLoad
{
[pv setDelegate:self];
[pv setDataSource:self];
[ll setText:[ap objectAtIndex:0]];
ap = [NSArray arrayWithObjects:#"AAA",#"BBB",#"CCC",#"DDD",#"EEE", nil];
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
NSURL *url = [NSURL fileURLWithPath:[NSString stringWithFormat:#"%#.m4a",[[NSBundle mainBundle] resourcePath]]];
NSError *error;
self.apr = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error];
apr.numberOfLoops = 2;
}
-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
return 1;
}
-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {
return [ap count];
}
-(NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent: (NSInteger)component {
return [ap objectAtIndex:row];
}
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent: (NSInteger)component {
si = [ap objectAtIndex:row];
[ll setText:si];
NSString *in = [NSString stringWithFormat:#"%#.jpg",si];
UIImage *tig = [UIImage imageNamed:in ];
[igv setImage:tig];
}
- (IBAction)utabu {
[self.apr play];
}
#end

Answer 1

Most likely the sound file could not be loaded. You should check the error variable after initializing the AVAudioPlayer.
The code for creating the URL objects is also wrong. You should use:
[[NSBundle mainBundle] URLForRessource:<filename> withExtension:"m4a"]
Also you would have to create a new AudioPlayer each time a sound file is selected.
Next time please use better variable names and not just two or three letter garbage.