private async void Registrera_Click(object sender, RoutedEventArgs e)
{
var selected = BookingListView.SelectedItems;
foreach (Booking booking in selected)
{
bool result = await Data.TestServer.Register(booking.ID);
if (result == true)
{
bookingViewModel.ChangeStatus(booking);
}
}
//BookingListView.Items = bookingViewModel;
}
