public void EmptyTable() { foreach (Blackboard board in Blackboards) { Blackboards.Remove(board); } foreach (Team team in Teams) { Teams.Remove(team); } foreach (User user in Users) { Users.Remove(user); } foreach (Administrator admin in Administrators) { Administrators.Remove(admin); } foreach (Colaborator colab in Colaborators) { Colaborators.Remove(colab); } foreach (Comment comment in Comments) { Comments.Remove(comment); } foreach (TextBox textbox in TextBoxes) { TextBoxes.Remove(textbox); } foreach (Image image in Images) { Images.Remove(image); } SaveChanges(); }