移动到背景时，AVPlayerLayer会让音乐停止播放一秒钟

Question

我删除/恢复AVPlayerLayer及其关联的AVPlayer，就像文档中的apple建议一样。

/* Remove the AVPlayerLayer from its associated AVPlayer
    once the app is in the background. */
- (void)applicationDidEnterBackground:(UIApplication *)application {
  MyPlayerLayerView *playerView = <#Get your player view#>;
  [[playerView playerLayer] setPlayer:nil]; // remove the player
}

/* Restore the AVPlayer when the app is active again. */
- (void)applicationDidBecomeActive:(UIApplication *)application {
  MyPlayerLayerView *playerView = <#Get your player view#>;
  [[playerView playerLayer] setPlayer:_player]; // restore the player
}

音乐继续播放，但切换到背景/前景时会有一点停顿和播放。

问题是如何避免它？