1. AVAudioPlayer 通過播放音頻發(fā)現(xiàn)AVAudioPlayer的duration屬性會變，當快播放到最后的時候duration屬性才是準確的，如下圖：

   
   
   image.png

所以解決辦法就是將AVAudioPlayer的currentTime設置到靠近最后位置，然后duration屬性就是正常了

self.audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:filePath error:&error];
    if (error) {
        NSLog(@"創(chuàng)建錄音播放對象發(fā)生錯誤，錯誤信息是：%@",error.localizedDescription);
    }else {
        self.audioPlayer.delegate = self;
        self.audioPlayer.meteringEnabled = YES;
        self.audioPlayer.numberOfLoops = 0;
        [self.audioPlayer prepareToPlay];
        
        // 獲取準確的時長
        NSLog(@"1.-----%f",self.audioPlayer.duration);
        _audioPlayer.currentTime = self.audioPlayer.duration;
        NSLog(@"2.-----%f",self.audioPlayer.duration);
        _audioPlayer.currentTime = 0;
        NSLog(@"3.-----%f",self.audioPlayer.duration);
    }