public static void SetRightBarItem(this IMvxBindingContextOwner controller, ICommand command = null)
{
var refresh = new UIBarButtonItem(UIBarButtonSystemItem.Refresh, (o, e) =>
{
if (command != null)
{
command.Execute(null);
}
});
controller.CreateBinding(refresh)
.For(t => t.Enabled)
.To <AbstractViewModel>(vm => vm.IsWorking)
.WithConversion("Negate")
.Apply();
(controller as UIViewController).NavigationItem.SetRightBarButtonItem(refresh, false);
}