private async void CheckBox_Click(object sender, RoutedEventArgs e) { CheckBox cb = (CheckBox)sender; if (cb.IsChecked == false) { progressbar.Value--; var percentageDone = progressbar.Value / progressbar.Maximum * 100; ItemsDone.Text = Math.Round(percentageDone).ToString() + "%"; } else { progressbar.Value++; var percentageDone = progressbar.Value / progressbar.Maximum * 100; ItemsDone.Text = Math.Round(percentageDone).ToString() + "%"; } string itemName = cb.Content.ToString(); await cvm.UpdateItem(itemName); }