private void GetTimezoneList() { progressIndicator.IsVisible = true; progressIndicator.IsIndeterminate = true; progressIndicator.Text = "Loading"; SystemTray.SetProgressIndicator(this, progressIndicator); TodoistService todoistService = new TodoistService(); todoistService.GetTimezoneList( (result) => { Dispatcher.BeginInvoke(() => { SearchTxtBox.IsEnabled = true; timezonesListBox.ItemsSource = result; }); }, (error) => { Dispatcher.BeginInvoke(() => { MessageBox.Show(error, "Metroist", MessageBoxButton.OK); }); }, () => { progressIndicator.IsVisible = false; progressIndicator.IsIndeterminate = false; }); }