private void IgnoredInterfacesListBox_OnSelectionChanged(object sender, SelectionChangedEventArgs e) { var selected = IgnoredInterfacesListBox.SelectedItems.OfType<NetworkInterface>().Select(x => x.Id).ToList(); Model.Online.IgnoredInterfaces = Model.NetworkInterfaces.Where(x => !selected.Contains(x.Id)).Select(x => x.Id); }