private void Add_Click(object sender, RoutedEventArgs e) { if (textBox.Text != "") { long id = _contentManager.AddTopic(textBox.Text, Convert.ToInt16(comboBox.SelectedValue)); if (id > 0) { _topics.Add(_contentManager.GetComponent(id) as Topic); listBox.Items.Refresh(); _saved = false; Confirm.IsEnabled = true; _empty = false; EditLessons.IsEnabled = true; } } }