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

        public static PdfPageLabelFormat[] GetPageLabelFormats(PdfReader reader)
        {
            PdfDictionary dict = reader.Catalog;
            PdfDictionary labels = (PdfDictionary)PdfReader.GetPdfObjectRelease(dict.Get(PdfName.PAGELABELS));
            if (labels == null)
                return null;
            Dictionary<int, PdfObject> numberTree = PdfNumberTree.ReadTree(labels);
            int[] numbers = new int[numberTree.Count];
            numberTree.Keys.CopyTo(numbers, 0);
            Array.Sort(numbers);
            PdfPageLabelFormat[] formats = new PdfPageLabelFormat[numberTree.Count];
            String prefix;
            int numberStyle;
            int pagecount;
            for (int k = 0; k < numbers.Length; ++k) {
                int key = numbers[k];
                PdfDictionary d = (PdfDictionary)PdfReader.GetPdfObjectRelease(numberTree[key]);
                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();
                } else {
                    prefix = "";
                }
                if (d.Contains(PdfName.S)) {
                    char type = ((PdfName)d.Get(PdfName.S)).ToString()[1];
                    switch (type) {
                        case 'R': numberStyle = UPPERCASE_ROMAN_NUMERALS; break;
                        case 'r': numberStyle = LOWERCASE_ROMAN_NUMERALS; break;
                        case 'A': numberStyle = UPPERCASE_LETTERS; break;
                        case 'a': numberStyle = LOWERCASE_LETTERS; break;
                        default: numberStyle = DECIMAL_ARABIC_NUMERALS; break;
                    }
                } else {
                    numberStyle = EMPTY;
                }
                formats[k] = new PdfPageLabelFormat(key + 1, numberStyle, prefix, pagecount);
            }
            return formats;
        }