CMTimeGetSeconds崩溃应用程序

Question

我使用 AVPlayer 播放视频链接并添加观察者以更新进度条。但随着时间超过10秒的视频，我的应用程序崩溃了。以下是我的代码

• 播放视频按钮：

  @IBAction func playVideoButtonPressed(sender: AnyObject) {
      if let contentUrl = curVideoModel?.video_Content_Url{
          player = AVPlayer(URL: NSURL(string: contentUrl))
          player?.actionAtItemEnd = AVPlayerActionAtItemEnd.None
          playerLayer = AVPlayerLayer(player: player)
          playerLayer!.frame = CGRectMake(0, 0, self.imvVideoThumbnail.frame.size.width, self.imvVideoThumbnail.frame.size.height)
          playerLayer!.backgroundColor = UIColor.blackColor().CGColor
          playerLayer!.videoGravity = AVLayerVideoGravityResizeAspectFill
          self.playvideoHolderView.layer.addSublayer(playerLayer)
          NSNotificationCenter.defaultCenter().addObserver(self, selector: "itemDidFinishPlaying:", name: AVPlayerItemDidPlayToEndTimeNotification, object: player?.currentItem)
          player?.addPeriodicTimeObserverForInterval(CMTimeMakeWithSeconds(1.0/60.0, Int32(NSEC_PER_SEC)), queue: nil, usingBlock: { (time) -> Void in
              self.updateProgressbar()
          })
          player!.play()
      }
  }
  

• 视频播放完毕后回调函数：

  NSNotificationCenter.defaultCenter().removeObserver(self, name: AVPlayerItemDidPlayToEndTimeNotification, object: player?.currentItem)
  self.progressBar.progress = 0
  if notification.name == AVPlayerItemDidPlayToEndTimeNotification{
      if player != nil{
          player?.pause()
      }
      if playerLayer != nil{
          playerLayer!.removeFromSuperlayer()
      }
  }
  

• 更新进度条的功能：

  var duration: Double
  var time: Double
  if player != nil{
       duration = CMTimeGetSeconds(player!.currentItem.duration)
       time = CMTimeGetSeconds(player!.currentTime())
  } else{
      duration = 0
      time = 0
  }
  self.lblTotalTime.text = "\(Int(duration))"
  self.lblCurrentTime.text = "\(Int(time))"
  self.progressBar.progress = Float(time / duration)
  

P / S：它在真实设备上崩溃（iPod touch iOS 8.3）。但是在模拟器上玩OK

编辑：也许Peter的评论是正确的。我检查：如果玩家！.currentItem.duration.value＆gt; 0 之前获取：持续时间= CMTimeGetSeconds（播放器！.currentItem.duration）。然后崩溃得到修复**