public override void ViewWillDisappear(bool animated)
 {
     try
     {
         base.ViewWillDisappear(animated);
         CommandBarHelper.PageWillDisappear(this);
     }
     catch (Exception e)
     {
         Application.Current.RaiseRecoverableUnhandledException(e);
     }
 }
            public PageViewController(Page page)
            {
                // Apply this check if we are compiling with the iOS 11 SDK or above
                if (!ScrollViewer.UseContentInsetAdjustmentBehavior)
                {
                    // This is deprecated on iOS 11+, we only set it on older versions.
                    AutomaticallyAdjustsScrollViewInsets = false;
                }

                // Allows Page content to extend under the UINavigationBar (even if opaque)
                ExtendedLayoutIncludesOpaqueBars = true;

                Page = page;
                View = Page;

                CommandBarHelper.PageCreated(this);
            }