public void DeleteCategorie() { MessageBoxResult result = MessageBox.Show("When you delete a Category, all Algorithms from this Category will be removed too." + "\n" + "By removing a Algorithm, all Results from this Algorithm will be deleted too." + "\n" + " Are you sure you want to delete this Category ?", "Delete Category?", MessageBoxButton.YesNo, MessageBoxImage.Warning, MessageBoxResult.No); switch (result) { case MessageBoxResult.Yes: CategorieDataService cds = new CategorieDataService(); cds.DeleteCategorie(SelectedCategorie); Messenger.Default.Send <UpdateFinishedMessage>(new UpdateFinishedMessage(UpdateFinishedMessage.MessageType.Deleted)); break; } }