“Adding Enable for commenting Adobe Reader” using Acrobat

Question

I am using iTextSharp to create on PDF document, later i want to add "Adding Enable for commenting Adobe Reader" using Acrobat, but i getting error as

You do not have permission to write to this file

Here my code used to create PDF file:

using (FileStream FS = new FileStream(dPDFFile_temp, FileMode.Create, FileAccess.Write, FileShare.None))
{
    using (Document Doc = new Document())
    {
        using (PdfCopy writer = new PdfCopy(Doc, FS))
        {
            Doc.Open();

            for (int i = 1; i <= R.NumberOfPages; i++)
            {
                writer.AddPage(writer.GetImportedPage(R, i));
            }
            Doc.Close();
        }
    }
}

Answer 1

You are asking something that is impossible: see http://support.itextpdf.com/node/24

Making a PDF reader-enabled requires a private key that is owned by Adobe. Any third party other than Adobe using that key, would be in violation with the law.