private void ListItemEdit_Click(object sender, RoutedEventArgs e)
        {
            var           val           = ((Button)sender).Tag;
            AddItemWindow addItemWindow = new AddItemWindow(_currentListId, "Edit", (int)val);

            addItemWindow.Show();
        }
        private void AddItem_Click(object sender, RoutedEventArgs e)
        {
            AddItemWindow addItemWindow = new AddItemWindow(_currentListId, "Add", 0);

            addItemWindow.Show();
        }