iOS 后台播放音乐

//后台播放音乐
-(void)playAudio{
    dispatch_queue_t dispatchQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    
    dispatch_async(dispatchQueue, ^(void) {
        NSError *audioSessionError = nil;
        AVAudioSession *audioSession = [AVAudioSession sharedInstance];
        if ([audioSession setCategory:AVAudioSessionCategoryPlayback error:&audioSessionError]){
            NSLog(@"Successfully set the audio session.");
        } else {
            NSLog(@"Could not set the audio session");
        }
  
        NSBundle *mainBundle = [NSBundle mainBundle];
        NSString *filePath = [mainBundle pathForResource:@"mySong" ofType:@"mp3"];
        NSData *fileData = [NSData dataWithContentsOfFile:filePath];
        NSError *error = nil;
        self.audioPlayer = [[AVAudioPlayer alloc] initWithData:fileData error:&error];
        
        if (self.audioPlayer != nil){
            self.audioPlayer.delegate = self;
            [self.audioPlayer setNumberOfLoops:-1];
            if ([self.audioPlayer prepareToPlay] && [self.audioPlayer play]){
                NSLog(@"Successfully started playing...");
            } else {
                NSLog(@"Failed to play.");
            }
        }
        
    });
    
}

调用方法一：
    SystemSoundID myAlertSound;
    NSURL *url = [NSURL URLWithString:@"/System/Library/Audio/UISounds/begin_video_record.caf"];
    AudioServicesCreateSystemSoundID((__bridge CFURLRef)(url), &myAlertSound);    
    AudioServicesPlaySystemSound(myAlertSound);
调用方法二：
    NSString *path = [[NSBundle bundleWithIdentifier:@"com.apple.UIKit"] pathForResource:@"Tock" ofType:@"aiff"];
    if (path) {
        SystemSoundID theSoundID;
        OSStatus error =  AudioServicesCreateSystemSoundID((__bridge CFURLRef)[NSURL fileURLWithPath:path], &theSoundID);
        if (error == kAudioServicesNoError) {
            AudioServicesPlaySystemSound(theSoundID);            
        }
        else
        {
            NSLog(@"Failed to create sound ");
        }
    }

iOS 后台播放音乐

原文：http://blog.csdn.net/etmanwenhan/article/details/48048247