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In this demo you can learn how to search a text in a PDF document. You can choose the text to search, you can choose to match or not the case or whole word only and you can choose the range of PDF pages where to search the text. The found text is highlighted in the original PDF.
Server Settings
IP: Port: Password:
PDF document:
Open the Input PDF Document
Text to search:
Page Range
From: To:
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C# Code
using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

using HiQPdfClient;

namespace HiQPdf_Demo
    public partial class SearchTextInPdf : System.Web.UI.Page
        protected void buttonSearchText_Click(object sender, EventArgs e)
            string serverIP = textBoxServerIP.Text;
            uint serverPort = uint.Parse(textBoxServerPort.Text);
            string serverPassword = textBoxServerPassword.Text;

            // get the PDF file
            string pdfFile = Server.MapPath("~") + @"\DemoFiles\Pdf\InputPdf.pdf";

            // get the text to search
            string textToSearch = textBoxTextToSearch.Text;

            // create the PDF text extractor
            PdfTextExtract pdfTextExtract = new PdfTextExtract(serverIP, serverPort);

            // use server password if necessary
            if (serverPassword.Length > 0)
                pdfTextExtract.ServerPassword = serverPassword;

            // set a demo serial number
            pdfTextExtract.SerialNumber = "YCgJMTAE-BiwJAhIB-EhlWTlBA-UEBRQFBA-U1FOUVJO-WVlZWQ==";

            int fromPdfPageNumber = int.Parse(textBoxFromPage.Text);
            int toPdfPageNumber = textBoxToPage.Text.Length > 0 ? int.Parse(textBoxToPage.Text) : 0;

            // search the text in PDF document
            PdfTextSearchItem[] searchTextInstances = pdfTextExtract.SearchText(pdfFile, textToSearch,
                        fromPdfPageNumber, toPdfPageNumber, checkBoxMatchCase.Checked, checkBoxMatchWholeWord.Checked);

            // assign a string to this variable if the PDF document to edit is password protected
            string pdfOpenPassword = null;

            // load the PDF file to highlight the searched text
            PdfDocument pdfDocument = PdfDocument.FromFile(serverIP, serverPort, serverPassword, pdfFile, pdfOpenPassword);

            // set a demo serial number
            pdfDocument.SerialNumber = "YCgJMTAE-BiwJAhIB-EhlWTlBA-UEBRQFBA-U1FOUVJO-WVlZWQ==";

            // highlight the searched text in PDF document
            foreach (PdfTextSearchItem searchTextInstance in searchTextInstances)
                PdfRectangle pdfRectangle = new PdfRectangle(searchTextInstance.BoundingRectangle);

                // set rectangle color and opacity
                pdfRectangle.BackColor = PdfColor.Yellow;
                pdfRectangle.Opacity = 30;

                // highlight the text
                pdfDocument.Pages[searchTextInstance.PdfPageNumber - 1].Layout(pdfRectangle);

            // write the modified PDF document
                // write the PDF document to a memory buffer
                byte[] pdfBuffer = pdfDocument.WriteToMemory();

                // inform the browser about the binary data format
                HttpContext.Current.Response.AddHeader("Content-Type", "application/pdf");

                // let the browser know how to open the PDF document and the file name
                HttpContext.Current.Response.AddHeader("Content-Disposition", String.Format("attachment; filename=SearchText.pdf; size={0}",

                // write the PDF buffer to HTTP response

                // call End() method of HTTP response to stop ASP.NET page processing

        protected void Page_Load(object sender, EventArgs e)
            if (!IsPostBack)
                string pageUri = HttpContext.Current.Request.Url.AbsoluteUri;
                hyperLinkOpenPdf.NavigateUrl = pageUri.Substring(0, pageUri.LastIndexOf('/')) + @"/DemoFiles/Pdf/InputPdf.pdf";