how to highlight a text or word in a pdf file using iTextsharp?

Question

I need to search a word in a existing pdf file and i want to highlight the text or word

and save the pdf file

I have an idea using PdfAnnotation.CreateMarku

Answer 1

@Jcis, I actually managed a workaround for handling multiple searches using your example as a starting point. I use your project as a reference in a c# project, and altered what it does. Instead of just highlighting I actually have it drawing a white rectangle around the search term, and then using the rectangle coordinates, place a form field. I also had to swap the contentbyte writing mode to getovercontent so that I block out the searched text entirely. What I actually did was to create a string array of search terms, and then using a for loop, I create as many different text fields as I need.

        Test.Form1 formBuilder = new Test.Form1();

        string[] fields = new string[] { "%AccountNumber%", "%MeterNumber%", "%EmailFieldHolder%", "%AddressFieldHolder%", "%EmptyFieldHolder%", "%CityStateZipFieldHolder%", "%emptyFieldHolder1%", "%emptyFieldHolder2%", "%emptyFieldHolder3%", "%emptyFieldHolder4%", "%emptyFieldHolder5%", "%emptyFieldHolder6%", "%emptyFieldHolder7%", "%emptyFieldHolder8%", "%SiteNameFieldHolder%", "%SiteNameFieldHolderWithExtraSpace%" };
        //int a = 0;
        for (int a = 0; a < fields.Length; )
        {
            string[] fieldNames = fields[a].Split('%');
            string[] fieldName = Regex.Split(fieldNames[1], "Field");
            formBuilder.PDFTextGetter(fields[a], StringComparison.CurrentCultureIgnoreCase, htmlToPdf, finalhtmlToPdf, fieldName[0]);
            File.Delete(htmlToPdf);
            System.Array.Clear(fieldNames, 0, 2);
            System.Array.Clear(fieldName, 0, 1);
            a++;
            if (a == fields.Length)
            {
                break;
            }
            string[] fieldNames1 = fields[a].Split('%');
            string[] fieldName1 = Regex.Split(fieldNames1[1], "Field");
            formBuilder.PDFTextGetter(fields[a], StringComparison.CurrentCultureIgnoreCase, finalhtmlToPdf, htmlToPdf, fieldName1[0]);
            File.Delete(finalhtmlToPdf);
            System.Array.Clear(fieldNames1, 0, 2);
            System.Array.Clear(fieldName1, 0, 1);
            a++;
        }

It bounces the PDFTextGetter function in your example back and forth between two files until I achieve the finished product. It works really well, and it would not have been possible without your initial project, so thank you for that. I also altered your VB to do the text field mapping like so;

           For Each rect As iTextSharp.text.Rectangle In MatchesFound
                cb.Rectangle(rect.Left, rect.Bottom + 1, rect.Width, rect.Height + 4)
                Dim field As New TextField(stamper.Writer, rect, FieldName & Fields)
                Dim form = stamper.AcroFields
                Dim fieldKeys = form.Fields.Keys
                stamper.AddAnnotation(field.GetTextField(), page)
                Fields += 1
            Next

Just figured I would share what I managed to do with your project as a backbone. It even increments the field names as I need them to. I also had to add a new parameter to your function, but that's not worth listing here. Thank you again for this great head start.