void OnFilterMenuItemClick(object sender, RoutedEventArgs e)
{
MenuItem senderItem = (MenuItem)sender;
MenuItem item = GetFilterMenuItem(SelectedFilter);
item.IsChecked = false;
senderItem.IsChecked = true;
SelectedFilter = senderItem.Tag as GalleryGroupFilter;
e.Handled = true;
RibbonPopup.CollapseCurrent();
}
