var pdfReader = new PdfReader("xxx.pdf");

             StreamWriter output = new StreamWriter(new FileStream("处理结果.txt", FileMode.Create));

             int pageCount = pdfReader.NumberOfPages;

             for (int pg = ; pg <= pageCount; pg++)

             {

                 ITextExtractionStrategy strategy = new SimpleTextExtractionStrategy();

                 var value = PdfTextExtractor.GetTextFromPage(pdfReader, pg, strategy);

                 value = value.Replace(" ", "");

                 Console.WriteLine(value);

                 output.Write(value);

             }

             output.Flush();

             output.Close();

             Console.Write("处理完毕");

             Console.ReadLine();