AVAudioPlayer线程实例化

Question

以下代码给出了AVAudioPlayer分配行标题的异常： 线程1断点1.2 我是否在实例化AVaudioPlayer时犯了错误？ 或者问题是由于玩家在不同的线程上播放的事实？

此处代码：

#import "songPlayer.h"

@implementation songPlayer

@synthesize audioPlayer;
@synthesize isPlaying;
@synthesize lastSongNumber;
@synthesize currentTimeSong;
@synthesize volume;
@synthesize audioFilesArray;

-(void)loadSoundFiles:(NSArray*)soundFiles{
    audioFilesArray = [[NSArray alloc]initWithArray:soundFiles];
}

-(void)loadSounds:(int)tagNumber{

    NSString *audiofile = [NSString stringWithFormat:@"%@", [audioFilesArray objectAtIndex:(tagNumber-201)]];
    if ([audiofile hasSuffix:@".mp3"]) {

    NSURL *url = [NSURL fileURLWithPath:[[NSBundle mainBundle]
                                         pathForResource:audiofile
                                         ofType:nil]];

    NSError *error;
    audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error];

    if (error)
    {
        NSLog(@"Error in audioPlayer: %@",
              [error localizedDescription]);
    } else {


        audioPlayer.delegate = self;
        if (!volume) {
            volume = 1.0;
        }
        [audioPlayer setVolume:volume];
        [audioPlayer prepareToPlay];
        if (!currentTimeSong) {
            currentTimeSong = 0;
        }
        audioPlayer.currentTime = currentTimeSong;
        }
    }
}

-(void)playOrStop:(int)tagNumber{
    if (audioPlayer.isPlaying > 0) {
        currentTimeSong =  audioPlayer.currentTime;
        [audioPlayer stop];
        audioPlayer = nil;
    if (tagNumber-200 != isPlaying) {
        [self playOrStop:tagNumber];
    } else {
        isPlaying = 0;
        return;
    }
    } else {
        isPlaying = tagNumber - 200;
        [self loadSounds:tagNumber];
        audioPlayer.currentTime = currentTimeSong;
        // Create an asynchronous background queue
       NSOperationQueue *queueSong = [[NSOperationQueue alloc] init];
        [queueSong addOperationWithBlock:
         ^{

             [audioPlayer play];
         }];
    }
}

-(void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag{
    NSLog(@"restart...");
    lastSongNumber = isPlaying + 200;
    audioPlayer.currentTime = 0;
    currentTimeSong = 0;
    isPlaying = 0;
    [self playOrStop:lastSongNumber];
}

@end