private void CategoryContentDialog_PrimaryButtonClick(ContentDialog sender, ContentDialogButtonClickEventArgs args)
 {
     if (string.IsNullOrEmpty(txtCategoryName.Text) || string.IsNullOrWhiteSpace(txtCategoryName.Text))
     {
         args.Cancel = true;
         txtCategoryName.PlaceholderText = AppConstants.AppMessages[AppConstants.UsedLanguage]["category_content_dialog_error"];
     }
     else
     {
         args.Cancel = false;
         if (_category == null)
         {
             _categoryCaption = txtCategoryName.Text;
             _return = CategoryContentDialogReturn.CategoryAdd;
         }
         else
         {
             _category.c_caption = txtCategoryName.Text;
             _return = CategoryContentDialogReturn.CategoryEdit;
         }
     }
 }
 private void CategoryContentDialog_SecondaryButtonClick(ContentDialog sender, ContentDialogButtonClickEventArgs args)
 {
     _return = CategoryContentDialogReturn.Cancel;
 }