AVURLAsset 获取录音文件时长

AVURLAsset* audioAsset =[AVURLAsset URLAssetWithURL:[NSURL URLWithString:message.text] options:nil];
CMTime audioDuration = audioAsset.duration;
float audioDurationSeconds =CMTimeGetSeconds(audioDuration);
_audio_timeLabel.text = [NSString stringWithFormat:@"%d", (int)audioDurationSeconds];