public static void RefreshAllPDF()
 {
     foreach (var articleId in ArticleListManager.GetListForArticleId())
     {
         string filepath = PDFFolder + articleId + ".pdf";
         if (System.IO.File.Exists(filepath))
         {
             System.IO.File.Delete(filepath);
         }
         ConvertUrlToPdf(BaseUrl + "/Article/SimplePdf?ArticleId=" + articleId, articleId);
     }
 }