protected async override void OnAppearing()
        {
            base.OnAppearing();
            //fixme loading on
            LoadingEventoInserirsci.IsRunning = true;
            LoadingEventoInserirsci.IsVisible = true;
            if (viewModel.Items.Count == 0)
            {
                //viewModel.LoadItemsCommand.Execute(null);
                await viewModel.LoadCategorie();
            }

            LoadingEventoInserirsci.IsRunning = false;
            LoadingEventoInserirsci.IsVisible = false;
            StackContent.IsVisible            = true;
            //fixme loading off
        }