private void AddUnit(object sender, RoutedEventArgs e) { if (!Validate()) { return; } Unit unit = new Unit(Host, name.Text, description.Text, city.SelectedValue as City, new HashSet <Amenity>(Amenities.SelectedItems), unit_type.SelectedValue as Unit.Type); Business.AddUnit(unit); UiUnits.Add(unit); Frame.GoBack(); }