iTextSharp.text.pdf.PdfReader.ReadPdf C# (CSharp) Метод

        protected internal virtual void ReadPdf() {
            try {
                fileLength = tokens.File.Length;
                pdfVersion = tokens.CheckPdfHeader();
                try {
                    ReadXref();
                }
                catch (Exception e) {
                    try {
                        rebuilt = true;
                        RebuildXref();
                        lastXref = -1;
                    }
                    catch (Exception ne) {
                        throw new InvalidPdfException("Rebuild failed: " + ne.Message + "; Original message: " + e.Message);
                    }
                }
                try {
                    ReadDocObj();
                }
                catch (Exception ne) {
                    if (ne is BadPasswordException)
                        throw new BadPasswordException(ne.Message);
                    if (rebuilt || encryptionError)
                        throw new InvalidPdfException(ne.Message);
                    rebuilt = true;
                    encrypted = false;
                    RebuildXref();
                    lastXref = -1;
                    ReadDocObj();
                }
                
                strings.Clear();
                ReadPages();
                EliminateSharedStreams();
                RemoveUnusedObjects();
            }
            finally {
                try {
                    tokens.Close();
                }
                catch {
                    // empty on purpose
                }
            }
        }