// what to do as the user types in searchbox
void SetContactsFiltered()
{
if (ContactsGrouped == null)
{
return;
}
ContactsFiltered = new ObservableCollection <Grouping <string, ContactCellViewModel> >(
ContactsGrouped.Select(group => new Grouping <string, ContactCellViewModel>(group.Key,
group.Where(contact => contact.Last.ToLower().Contains(SearchText.ToLower()) ||
contact.First.ToLower().Contains(SearchText.ToLower())))).Where(group => group.Any())
);
}
