使用AVPlayer自定义播放器，重写网络请求部分，实现边下边播

• (void)viewDidLoad {

  [super viewDidLoad];

  _VView = [[XPVideoPlayerView alloc]init];

  [self.view setBackgroundColor:[UIColor whiteColor]];

  _VView = [[XPVideoPlayerView alloc] initWithFrame:CGRectMake(0, CGRectGetHeight([[UIApplication sharedApplication]statusBarFrame])+CGRectGetHeight(self.navigationController.navigationBar.frame), CGRectGetWidth(self.view.frame),CGRectGetWidth(self.view.frame)*9/16)];

  _VView.delegate = self;

  [_VView setVideoFillMode:AVLayerVideoGravityResizeAspect];

  XPVideoPlayer * player = [[XPVideoPlayer alloc]init];

  [player enableTimeUpdates];

  [player enableAirplay];

  [player setURL:[NSURL URLWithString:@"https://dn-xpdu.qbox.me/A%20Shaw%20way%20to%20fly%20Alexander%20technique..Butterfly%20lesson%201.mp4"]];

  [player setSupportCache:YES];

  [_VView setPlayer:player];

  [player play];

  [_VView setFrame:[UIScreen mainScreen].bounds];

  [self.view addSubview:_VView];

}