private void BtnDelete_Click(object sender, RoutedEventArgs e) { Tickets selectedTicket = DGTickets.SelectedItem as Tickets; if (SelectedTicket(selectedTicket)) { if (MessageBox.Show("Are you sure that you want to delete this ticket?", "Confirm", MessageBoxButton.YesNo).Equals(MessageBoxResult.Yes)) { foreach (var seat in Data.Instance.SeatAvailable.ToList()) { if (seat.SeatLabel.Equals(selectedTicket.SeatNum.SeatLabel)) { seat.SeatState = true; seat.ChangeSeat(); view.Refresh(); } } int index = IndexOfSelectedTicket(selectedTicket.CurrentUser); selectedTicket.Active = true; selectedTicket.ChangeTicket(); Data.Instance.Tickets[index].Active = true; view.Refresh(); } } }