//save button clicked private async void appBarSave_Click(object sender, EventArgs e) { if (string.IsNullOrWhiteSpace(txtListItemName.Text) == false) { progress.Visibility = System.Windows.Visibility.Visible; (sender as ApplicationBarIconButton).IsEnabled = false; try { //save the list item var todoItem = new TodoItem { Name = txtListItemName.Text.Trim() }; await todoItem.Save(); //clear the text field txtListItemName.Text = string.Empty; //update the local list App.ViewModel.Add(todoItem); App.ViewModel.Items.SortByDate(); } catch (Exception) { MessageBox.Show("Failed to save the todo item", "Operation failed", MessageBoxButton.OK); } progress.Visibility = System.Windows.Visibility.Collapsed; (sender as ApplicationBarIconButton).IsEnabled = true; } Cancel(); }