Question

当在tableView中选择一个单元格时，我需要重新加载该行，并设置一些定时器以在某些日期触发AVAudioPlayers（此设置需要几秒钟，但计时器已开始按照预期开始）。

但是，重新加载表格视图行（有效地突出显示该行）会延迟一段时间。

在选择保留良好的UI体验时，我需要重新加载行作为第一件事。

我试图将重新加载部分放在主线程中，如下所示：UITableView reloadData() gets fired but delays

由于某种原因，这不起作用：

override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
  // do some things

  dispatch_async(dispatch_get_main_queue(), {
    tableView.reloadRowsAtIndexPaths([indexPath], withRowAnimation: .None)
  })

  setupTimersToFireAtDate() 
}

func setupTimersToFireAtDate() {
  let start = NSDate()
  // These are Float as they will be calculated with other Float values
  var accumulatedTime: Float = 0.0
  var elapsedTime: Float = 0.0

  for event in events {
    var player = AVAudioPlayer()
    accumulatedTime += event.time

    do {
      // the urls array keeps urls to the sounds. For this example, I've set the index to be random, since it doesn't really matter.
      player = try AVAudioPlayer(contentsOfURL: urls[Int.random])
      // Players need to be maintained in order to playback, each player is removed with the audioPlayerDidFinishPlaying AVAudioPlayerDelegate method.
      players += [player]
    } catch let error as NSError {
      loadError = error
    }

    elapsedTime = Float(NSDate().timeIntervalSinceDate(start))

    // Some other calculations in between here.

    player.prepareToPlay()
    player.delegate = self
    player.currentTime = 0.0

    player.playAtTime(player.deviceCurrentTime + (NSTimeInterval(accumulatedNoteTime - elapsedTime)))
  }
}

我可能在这里遗漏了一些东西，因为我不知道为什么这不起作用。

非常感谢任何帮助！

Answer 1

最简单的解决方案是将呼叫延迟到setupTimersToFireDate，以便可以立即调用reloadRowsAtIndexPaths。

override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    // do some things

    tableView.reloadRowsAtIndexPaths([indexPath], withRowAnimation: .None)

    dispatch_async(dispatch_get_main_queue(), {
        setupTimersToFireAtDate() 
    })
}

表格视图中的重新加载行会无意中延迟

1 个答案: