iTextSharp.text.pdf.PdfStamper.GetOverContent C# (CSharp) Метод

        public PdfContentByte GetOverContent(int pageNum)
        {
            return stamper.GetOverContent(pageNum);
        }

 /// <summary>
 /// Fills out and flattens a form with the name, company and country.
 /// </summary>
 /// <param name="src"> the path to the original form </param>
 /// <param name="dest"> the path to the filled out form </param>
 public void ManipulatePdf(String src, String dest)
 {
     PdfReader reader = new PdfReader(src);
     PdfStamper stamper = new PdfStamper(reader, new FileStream(dest, FileMode.Create));
     int n = reader.NumberOfPages;
     Rectangle pagesize;
     for (int i = 1; i <= n; i++)
     {
         PdfContentByte over = stamper.GetOverContent(i);
         pagesize = reader.GetPageSize(i);
         float x = (pagesize.Left + pagesize.Right) / 2;
         float y = (pagesize.Bottom + pagesize.Top) / 2;
         PdfGState gs = new PdfGState();
         gs.FillOpacity = 0.3f;
         over.SaveState();
         over.SetGState(gs);
         over.SetRGBColorFill(200, 200, 0);
         ColumnText.ShowTextAligned(over, Element.ALIGN_CENTER,
             new Phrase("Watermark", new Font(Font.FontFamily.HELVETICA, 120)),
             x, y, 45);
         over.RestoreState();
     }
     stamper.Close();
     reader.Close();
 }