public ContentResult BlogGroups() { StringBuilder sb = new StringBuilder(); sb.Append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>"); sb.Append("<urlset xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\">"); foreach (var item in Groups.GetByGroupType(GroupType.Blogs)) { var lastestDate = Articles.LatestDateByGroupID(item.ID); sb.Append(" <url>"); sb.Append(" <loc>" + StaticValues.WebsiteUrl + UrlProvider.GetBlogGroupUrl(item.TitleEn) + "</loc>"); sb.Append(" <lastmod>" + lastestDate.ToString("yyyy-MM-dd") + "</lastmod>"); sb.Append(" </url> "); } sb.Append("</urlset>"); return(Content(sb.ToString(), "text/xml")); }