public void updateSubscriberTopics(string id) { this.Invoke(new Action(() => { if (uxSubs.SelectedItem != null) { if (uxSubs.SelectedItem.ToString() == id) { uxSubTopics.Items.Clear(); List <string> topics = controller.getSubscriberTopicsByID(id); foreach (string topic in topics) { uxSubTopics.Items.Add(topic); } } } })); }