private void CreateButton_Click(object sender, RoutedEventArgs e)
 {
     Models.TodoItem TodoToCreate = new Models.TodoItem(TitleTextBox.Text,
                                                        DetailTextBox.Text, DueDatePicker.Date, TodoImage.Source, ImageFile);
     if (shareOp == null)
     {
         if (TodoToCreate.TodoInfoValidator())
         {
             ViewModel.AddTodoItem(TodoToCreate);
             ViewModel.NewestItem = TodoToCreate;
             Frame.Navigate(typeof(MainPage), ViewModel);
         }
     }
     else
     { // on sharing
         shareOp.ReportCompleted();
     }
 }