I'm posting this mostly for my own benefit since every time I need it I spend 20 minutes googling around to get the code snippet again.

So here's the article: LINK

Here's the Code:

TelerikReportingExportToPdf.csView on GitHub
void ExportToPDF(Telerik.Reporting.Report reportToExport)
    {
        ReportProcessor reportProcessor = new ReportProcessor();
        RenderingResult result = reportProcessor.RenderReport("PDF", reportToExport, null);
  
    string fileName = result.DocumentName + ".pdf";

    Response.Clear();
    Response.ContentType = result.MimeType;
    Response.Cache.SetCacheability(HttpCacheability.Private);
    Response.Expires = -1;
    Response.Buffer = true;

    Response.AddHeader("Content-Disposition",
                       string.Format("{0};FileName=\"{1}\"",
                                     "attachment",
                                     fileName));

    Response.BinaryWrite(result.DocumentBytes);
    Response.End();
}</code></pre></div>

So you can change the extensions to the following:

  • IMAGE
  • PDF
  • RTF
  • MHTML
  • XLS
  • CSV
  • XPS

This comes from here: LINK