PDF from byte array from sql server in mvc

public byte[] PDF(List<DeliveryOrderDetail> deliveryOrdList)
        {
            byte[] result;
            string headingText = "Guide";
            try
            {

                using (MemoryStream ms = new MemoryStream())
                {
                    Document doc = new Document();
                    PdfWriter.GetInstance(doc, ms).CloseStream = false;
                    PdfPTable pdfTab = new PdfPTable(3);
                    Paragraph heading = new Paragraph(headingText, new Font(Font.TIMES_ROMAN, 18f, Font.NORMAL, Color.BLACK));
                    Paragraph ItemDetail = new Paragraph("Items in Delivery Order Box:", new Font(Font.TIMES_ROMAN, 12f, Font.NORMAL, Color.BLACK));
                    heading.Alignment = Element.ALIGN_CENTER;
                    ItemDetail.Alignment = Element.ALIGN_CENTER;
                    doc.Open();
                    doc.Add(heading);
                    pdfTab.HorizontalAlignment = 1; // 0- Left, 1- Center, 2- right
                    pdfTab.SpacingBefore = 20f;
                    pdfTab.SpacingAfter = 20f;
                    // pdfTab.AddCell("Sl. No.");
                    pdfTab.AddCell("ItemName");
                    pdfTab.AddCell("BoxId");
                    pdfTab.AddCell("Manufacturer");
                    doc.Add(ItemDetail);
                    foreach (var item in deliveryOrdList)
                    {

                        pdfTab.AddCell(item.Name);
                        pdfTab.AddCell(item.Id.ToString());
                        pdfTab.AddCell(item.Manufacturer);

                    }

                    doc.Add(pdfTab);
                    doc.Close();
                    result = ms.GetBuffer();
                }


                return result;

            }
            catch(Exception e )
            {

            }
            return null;
        }

<script type="text/javascript">
     $(document).ready(function () {
         $('.Pdf').click(function () {

             var pdf = $(this).closest('tr').find('td:eq(0) input').val();;

             alert(pdf);
             $.ajax({
                 url: "/ship/PDF",
                 type: "POST",
                 dataType: "json",
                 data:JSON.stringify({ pdf: pdf }),
                 //data:{pdf:pdf},
                 cache: false,
                 dataType: "json",
                 contentType: "application/json; charset=utf-8"

             })
         })
     })
 </script>

[HttpPost]
public ActionResult PDF(string  pdf)
{
    try
    {

        byte[] byteInfo =  System.Text.Encoding.UTF8.GetBytes(pdf);
        MemoryStream ms = new MemoryStream();
        workStream.Write(byteInfo, 0, byteInfo.Length);
        workStream.Position = 0;


        return new FileStreamResult(ms, "application/pdf");

    }
    //to catch the exception
    catch (Exception _Exception)
    {

    }
    return null;
}

System.IO.File.WriteAllBytes(@"D:\personal\testpdf.pdf", byteInfo);