我正在尝试使用最近在IOS9中引入的AVPictureInPictureController播放视频，使用此代码:AVPlayer*_AVPlayer=[AVPlayerplayerWithURL:url];AVPlayerLayer*_layer=[AVPlayerLayerplayerLayerWithPlayer:_AVPlayer];_layer.frame=[[UIApplicationsharedApplication]delegate].window.bounds;AVPictureInPictureController*_AVPictureInPictureContro