用背景颜色突出显示pdf文件中的文本

Question

需要一种在PDF格式中使用背景颜色突出显示特定文本的解决方案，并且最终结果应在新的pdf文件中。.我尝试了几种基于itextSharp的解决方案，但到目前为止还没有运气。您能帮我解决这个问题吗？

private static void PDFTextGetter(string pSearch, StringComparison sc, string sourceFile, string destinationFile)
    {
        PdfStamper stamper;
        PdfContentByte cb;

        var pReader = new PdfReader(sourceFile);

        using (FileStream fs = new FileStream(destinationFile, FileMode.Create))
        {
            stamper = new PdfStamper(pReader, fs);
            for (int page = 1; page <= pReader.NumberOfPages; page++)
            {
                var strategy = new myLocationTextExtractionStrategy();
                cb = stamper.GetUnderContent(page);
                strategy.UndercontentCharacterSpacing = cb.CharacterSpacing;
                strategy.UndercontentHorizontalScaling = cb.HorizontalScaling;


                string currentText = PdfTextExtractor.GetTextFromPage(pReader, page, strategy);


                List<iTextSharp.text.Rectangle> matchesFound = strategy.GetTextLocations(pSearch, sc);

                 cb.SetColorFill(BaseColor.YELLOW);


                foreach (iTextSharp.text.Rectangle rect in matchesFound)
                    cb.Rectangle(rect.Left, rect.Bottom, rect.Width, rect.Height);

                cb.Fill();


            }
            stamper.Close();
            pReader.Close();
        }
    }