public override void ViewWillAppear(bool animated)
{
LoadExtensionItem ();
timer = NSTimer.CreateRepeatingScheduledTimer (2, Refresh);
Refresh (timer);
base.ViewWillAppear (animated);
Title = "Select device";
// "CompleteRequest" -> Calling this method eventually dismisses the app extension’s view controller.
NavigationItem.RightBarButtonItem = new UIBarButtonItem (UIBarButtonSystemItem.Done,
(sender, e) => Dismiss ());
}