iOS 网页(WKWebView)加载视频后没有状态栏了

//在web页面直接添加观察者
[[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(windowDidBecomeHidden:) name:UIWindowDidBecomeHiddenNotification object:nil];

-(void)windowDidBecomeHidden:(NSNotification *)noti{
    
    UIWindow * win = (UIWindow *)noti.object;
    
    if(win){
        
        UIViewController *rootVC = win.rootViewController;
        
        NSArray<__kindof UIViewController *> *vcs = rootVC.childViewControllers;
        
        if([vcs.firstObject isKindOfClass:NSClassFromString(@"AVPlayerViewController")]){
            
            [[UIApplication sharedApplication] setStatusBarHidden:NO withAnimation:UIStatusBarAnimationNone];
        }
    }
}