public override DataTemplate SelectTemplate(object item, DependencyObject container)
        {
            ContentPresenter cp = container as ContentPresenter;

            if (cp != null)
            {
                CollectionViewGroup cvg = cp.Content as CollectionViewGroup;

                if (cvg.Items.Count > 0)
                {
                    UserCase stinfo = cvg.Items[0] as UserCase;

                    if (stinfo != null)
                    {
                        return(GroupCategoryTemplate);
                    }
                    else
                    {
                        return(GroupNameTemplate);
                    }
                }
            }

            return(base.SelectTemplate(item, container));
        }
        private void MouseLeftButtonDownClassHandler(object sender, RoutedEventArgs e)
        {
            UserCase item = ((FrameworkElement)sender).DataContext as UserCase;

            if (item != null)
            {
                _listBox.SelectedItem = item;
                RaiseSelectedChipEvent(_listBox.SelectedItem, false);
                _searchBox.Text = null;
            }
        }