本地文件、网络文件，区别就是URL创建方式
1、使用AVPlayerItem与AVPlayer（这个简单，只需要设置回调），而不是AVAudioPlayer（这个麻烦，需要设置代理、计时器等等）
2、设置AVPlayerItem的url，然后AVPlayer播放这个AVPlayerItem，在AVPlayer播放AVPlayerItem回调读取播放完毕后，重新设置进度，具体如图
NSString *document=[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)firstObject];
NSString *audioPath = [document stringByAppendingPathComponent:@"voice"];
NSString *toUrl = [audioPath stringByAppendingPathComponent:self.filepatch];
NSURL *musicURL = [NSURL fileURLWithPath:toUrl];
NSError *error;
self.player = [[AVPlayer alloc] initWithPlayerItem:nil];
AVPlayerItem * songItem = [[AVPlayerItem alloc]initWithURL:musicURL];
__weak typeof(songItem) weakSong =songItem;
[self.player replaceCurrentItemWithPlayerItem:songItem];
self.player.volume = 1.0;
weakify(self)
[_player addPeriodicTimeObserverForInterval:CMTimeMakeWithSeconds(1, 1) queue:NULL usingBlock:^(CMTime time) {
//进度 当前时间/总时间
wSelf.progress.progress =CMTimeGetSeconds(wSelf.player.currentItem.currentTime)/CMTimeGetSeconds(wSelf.player.currentItem.duration);
NSLog(@"per:%f-%f",CMTimeGetSeconds(wSelf.player.currentItem.currentTime),CMTimeGetSeconds(wSelf.player.currentItem.duration));
if ( wSelf.progress.progress==1) {
[weakSong seekToTime:kCMTimeZero];
[wSelf.player play];
}
wSelf.label.text = [NSString stringWithFormat:@"%.2f秒|%.2f秒",CMTimeGetSeconds(wSelf.player.currentItem.currentTime),CMTimeGetSeconds(wSelf.player.currentItem.duration)];
}];
[self.player play];