如何在通知扩展服务中播放声音？

Question

我的代码：

NSString *soundFilePath = [[NSBundle mainBundle] pathForResource:@"autumn_leaves" ofType:@"m4a"];
NSURL *soundFileURL = [NSURL fileURLWithPath:soundFilePath];

NSError *error;
AVAudioPlayer *player = [[AVAudioPlayer alloc] initWithContentsOfURL:soundFileURL
                                               error:&error];
player.numberOfLoops = -1; //Infinite

[player play];

如何在通知扩展服务中使用avplayer播放声音？