iTextSharp.text.pdf.PdfPageLabels.GetPageLabels C# (CSharp) Метод

        public static String[] GetPageLabels(PdfReader reader)
        {
            int n = reader.NumberOfPages;

            PdfDictionary dict = reader.Catalog;
            PdfDictionary labels = (PdfDictionary)PdfReader.GetPdfObjectRelease(dict.Get(PdfName.PAGELABELS));
            if (labels == null)
                return null;

            String[] labelstrings = new String[n];
            Dictionary<int, PdfObject> numberTree = PdfNumberTree.ReadTree(labels);

            int pagecount = 1;
            String prefix = "";
            char type = 'D';
            for (int i = 0; i < n; i++) {
                if (numberTree.ContainsKey(i)) {
                    PdfDictionary d = (PdfDictionary)PdfReader.GetPdfObjectRelease(numberTree[i]);
                    if (d.Contains(PdfName.ST)) {
                        pagecount = ((PdfNumber)d.Get(PdfName.ST)).IntValue;
                    }
                    else {
                        pagecount = 1;
                    }
                    if (d.Contains(PdfName.P)) {
                        prefix = ((PdfString)d.Get(PdfName.P)).ToUnicodeString();
                    }
                    if (d.Contains(PdfName.S)) {
                        type = ((PdfName)d.Get(PdfName.S)).ToString()[1];
                    }
                    else {
                        type = 'e';
                    }
                }
                switch (type) {
                default:
                    labelstrings[i] = prefix + pagecount;
                    break;
                case 'R':
                    labelstrings[i] = prefix + RomanNumberFactory.GetUpperCaseString(pagecount);
                    break;
                case 'r':
                    labelstrings[i] = prefix + RomanNumberFactory.GetLowerCaseString(pagecount);
                    break;
                case 'A':
                    labelstrings[i] = prefix + RomanAlphabetFactory.GetUpperCaseString(pagecount);
                    break;
                case 'a':
                    labelstrings[i] = prefix + RomanAlphabetFactory.GetLowerCaseString(pagecount);
                    break;
                case 'e':
                    labelstrings[i] = prefix;
                    break;
                }
                pagecount++;
            }
            return labelstrings;
        }