> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/xamarin/get-started/samples/textsearchtest.md). # TextSearch Sample C# code for using Apryse SDK to search text on PDF pages using regular expressions. The TextSearch utility class builds on functionality available in TextExtractor to simplify most common searc Sample C# code for using Apryse SDK to search text on PDF pages using regular expressions. The TextSearch utility class builds on functionality available in [TextExtractor](/xamarin/get-started/samples.md#textextract) to simplify most common search operations. Learn more about our [Xamarin SDK](/core/get-started/frameworks/dotnet.md) and [PDF Indexed Search Library](/core/search/search.md). {% tabs %} {% tab title="C#" %} {% code lineNumbers="true" %} ```csharp // // Copyright (c) 2001-2021 by PDFTron Systems Inc. All Rights Reserved. // using System; using pdftron; using pdftron.Common; using pdftron.Filters; using pdftron.SDF; using pdftron.PDF; using NUnit.Framework; namespace MiscellaneousSamples { // This sample illustrates various text search capabilities of PDFNet. [TestFixture] public class TextSearchTest { [Test] public static void Sample() { // Relative path to the folder containing test files. const string input_path = "TestFiles/"; // Sample code showing how to use high-level text extraction APIs. try { using (PDFDoc doc = new PDFDoc(Utils.GetAssetTempFile(input_path + "credit card numbers.pdf"))) { doc.InitSecurityHandler(); Int32 page_num = 0; String result_str = "", ambient_string = ""; Highlights hlts = new Highlights(); TextSearch txt_search = new TextSearch(); Int32 mode = (Int32)(TextSearch.SearchMode.e_whole_word | TextSearch.SearchMode.e_page_stop | TextSearch.SearchMode.e_highlight); String pattern = "joHn sMiTh"; //call Begin() method to initialize the text search. txt_search.Begin( doc, pattern, mode, -1, -1 ); int step = 0; //call Run() method iteratively to find all matching instances. while ( true ) { TextSearch.ResultCode code = txt_search.Run(ref page_num, ref result_str, ref ambient_string, hlts ); if ( code == TextSearch.ResultCode.e_found ) { if ( step == 0 ) { //step 0: found "John Smith" //note that, here, 'ambient_string' and 'hlts' are not written to, //as 'e_ambient_string' and 'e_highlight' are not set. Console.WriteLine(result_str + "'s credit card number is: "); //now switch to using regular expressions to find John's credit card number mode = txt_search.GetMode(); mode |= (Int32)(TextSearch.SearchMode.e_reg_expression | TextSearch.SearchMode.e_highlight); txt_search.SetMode(mode); pattern = "\\d{4}-\\d{4}-\\d{4}-\\d{4}"; //or "(\\d{4}-){3}\\d{4}" txt_search.SetPattern(pattern); ++step; } else if ( step == 1 ) { //step 1: found John's credit card number //result_str.ConvertToAscii(char_buf, 32, true); //cout << " " << char_buf << endl; Console.WriteLine(" " + result_str); //note that, here, 'hlts' is written to, as 'e_highlight' has been set. //output the highlight info of the credit card number hlts.Begin(doc); while (hlts.HasNext()) { Console.WriteLine("The current highlight is from page: " + hlts.GetCurrentPageNumber()); hlts.Next(); } //see if there is an AMEX card number pattern = "\\d{4}-\\d{6}-\\d{5}"; txt_search.SetPattern(pattern); ++step; } else if ( step == 2 ) { //found an AMEX card number Console.WriteLine("\nThere is an AMEX card number:\n " + result_str); //change mode to find the owner of the credit card; supposedly, the owner's //name proceeds the number mode = txt_search.GetMode(); mode |= (Int32)(TextSearch.SearchMode.e_search_up); txt_search.SetMode(mode); pattern = "[A-z]++ [A-z]++"; txt_search.SetPattern(pattern); ++step; } else if ( step == 3 ) { //found the owner's name of the AMEX card Console.WriteLine("Is the owner's name:\n " + result_str + "?"); //add a link annotation based on the location of the found instance hlts.Begin(doc); while (hlts.HasNext()) { Page cur_page = doc.GetPage(hlts.GetCurrentPageNumber()); double[] quads = hlts.GetCurrentQuads(); int quad_count = quads.Length / 8; for (int i = 0; i < quad_count; ++i) { //assume each quad is an axis-aligned rectangle int offset = 8 * i; double x1 = Math.Min(Math.Min(Math.Min(quads[offset + 0], quads[offset + 2]), quads[offset + 4]), quads[offset + 6]); double x2 = Math.Max(Math.Max(Math.Max(quads[offset + 0], quads[offset + 2]), quads[offset + 4]), quads[offset + 6]); double y1 = Math.Min(Math.Min(Math.Min(quads[offset + 1], quads[offset + 3]), quads[offset + 5]), quads[offset + 7]); double y2 = Math.Max(Math.Max(Math.Max(quads[offset + 1], quads[offset + 3]), quads[offset + 5]), quads[offset + 7]); pdftron.PDF.Annots.Link hyper_link = pdftron.PDF.Annots.Link.Create(doc, new Rect(x1, y1, x2, y2), pdftron.PDF.Action.CreateURI(doc, "http://www.pdftron.com")); hyper_link.RefreshAppearance(); cur_page.AnnotPushBack(hyper_link); } hlts.Next(); } doc.Save(Utils.CreateExternalFile("credit card numbers_linked.pdf"), SDFDoc.SaveOptions.e_linearized); break; } } else if ( code == TextSearch.ResultCode.e_page ) { //you can update your UI here, if needed } else { break; } } } } catch (PDFNetException e) { Console.WriteLine(e.Message); Assert.True(false); } } } } ``` {% endcode %} {% endtab %} {% endtabs %} --- # Agent Instructions This documentation is published with GitBook. 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