private void DisplayNameTextBox_KeyDown(object sender, KeyEventArgs e)
 {
     if (e.Key == Key.Enter)
     {
         if (App.IsTrial)
         {
             DatePicker.Focus();
         }
         else
         {
             GroupTextBox.Focus();
         }
     }
 }
        private void BarcodeTextBox_KeyDown(object sender, KeyEventArgs e)
        {
            switch (e.Key)
            {
            case Key.Enter: {
                if (BarcodeTextBox.Text.Trim().Length == 0)
                {
                    BarcodeTextBox.Text = "Undefined";
                }
                GroupTextBox.Focus();
            } break;

            default: break;
            }//switch
        }