iTextSharp.text.pdf.AcroFields.UpdateByteRange C# (CSharp) Метод

        private void UpdateByteRange(PdfPKCS7 pkcs7, PdfDictionary v) {
            PdfArray b = v.GetAsArray(PdfName.BYTERANGE);
            RandomAccessFileOrArray rf = reader.SafeFile;
            try {
                rf.ReOpen();
                byte[] buf = new byte[8192];
                for (int k = 0; k < b.Size; ++k) {
                    int start = b.GetAsNumber(k).IntValue;
                    int length = b.GetAsNumber(++k).IntValue;
                    rf.Seek(start);
                    while (length > 0) {
                        int rd = rf.Read(buf, 0, Math.Min(length, buf.Length));
                        if (rd <= 0)
                            break;
                        length -= rd;
                        pkcs7.Update(buf, 0, rd);
                    }
                }
            }
            finally {
                try{rf.Close();}catch{}
            }
        }