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Replace Text in PDF with C# REST API

This short tutorial explains how to replace text in PDF with C# REST API. You will learn to replace words in PDF with C# RESTful Service using a .NET-based Cloud SDK. It will guide you in finding words by comparing strings or using regex and perform this task on a single page or the entire PDF file.

Prerequisite

Steps to Replace Text in PDF Online with C# REST Interface

  1. Configure the PdfApi object using the key and application SID to replace the text
  2. Upload the source PDF file into the Cloud storage for finding and replacing text
  3. Create the list of TextReplace objects with a pair of old and new strings
  4. Create the text replace request using the TextReplaceListRequest class by providing the TextReplace list
  5. Call the PostDocumentTextReplace to replace all the old strings with new strings
  6. Download the output file on the successful response from the API

The above steps describe how to find and replace word in PDF with C# REST API. Create the PdfApi object containing the features to work with a PDF file, upload the source PDF file to online Cloud storage, create a list of pairs of words of old and new strings, and create a request object using this pair of lists. Call the PostDocumentTextReplace() method to replace the listed words and save the output file.

Code to Find and Replace Text in PDF with C# .NET-based API

using System;
using System.IO;
using Aspose.Pdf.Cloud.Sdk.Api;
using Aspose.Pdf.Cloud.Sdk.Model;
using System.Collections.Generic;
namespace Aspose.PDF.Cloud.Examples.Kb
{
public class PdfTasks
{
public static void ReplaceTextInPdf()
{
PdfApi pdfApi = new PdfApi("APP_KEY", "APP_SID");
String fileName = "TextAndImages.pdf";
try
{
// Upload source file to aspose cloud storage for replacing words
FilesUploadResult result = pdfApi.UploadFile(fileName, new MemoryStream(File.ReadAllBytes(fileName)));
if (result.Errors.Count == 0)
{
List<TextReplace> textReplaces = new List<TextReplace>()
{
new TextReplace("English", "English Subject", false),
new TextReplace("Math", "Math Subject", false),
new TextReplace("Science", "Science Subject", false),
};
TextReplaceListRequest textReplaceListRequest = new TextReplaceListRequest(textReplaces);
TextReplaceResponse response = pdfApi.PostDocumentTextReplace(fileName, textReplaceListRequest);
if (response.Status == "OK")
{
// Download created pdf file
Stream storageRes = pdfApi.DownloadFile(fileName);
FileStream fileStream = new FileStream("output.pdf", FileMode.Create, FileAccess.Write);
storageRes.CopyTo(fileStream);
}
}
}
catch (Exception ex)
{
Console.WriteLine("error:" + ex.Message + "\n" + ex.StackTrace);
}
}
}
}
view raw Replace Text in PDF with C# REST API.cs hosted with ❤ by GitHub

This code demonstrates the process to replace text in PDF file with C# REST Interface. You may use the list of strings or Regex expression while searching the strings in the complete document. If you want to replace text in a single page of the uploaded PDF file, use the PostPageTextReplace() method with the target page number.

This article has taught us to search and replace text in a PDF file. If you want to add a new page to a PDF file, refer to the article on Add new page in PDF with C# REST API.

 

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