How to redact content from PDF document in ASP.NET Core

The Syncfusion Essential® PDF is a .NET Core PDF library used to create, read, and edit PDF documents. Using this library, you can redact content from the PDF documents in the ASP.NET Core platform.

Steps to redact content from the PDF document in ASP.NET Core using C#

1. Create a new ASP.NET Core MVC application.

2. Install the Syncfusion.Pdf.Imaging.Net.Core NuGet packages as a reference to your .NET Core project from NuGet.org.

3. Add a new button (Redact PDF) in the Index.cshtml as follows.

@{ Html.BeginForm("RedactPDF", "Home", FormMethod.Post);
    {
        <input type="submit" value="Redact PDF Document" class=" btn" />
    }
}

4. Include the following namespaces in the HomeController.cs file.

using Syncfusion.Pdf;
using Syncfusion.Pdf.Parsing;
using Syncfusion.Pdf.Redaction;
using System.IO;

5. Add a new action method RedactPDF in the HomeController.cs and include the following code sample to redact the content from a PDF file and download it.

//To get the content root path of a project.
private readonly IHostingEnvironment _hostingEnvironment;
public HomeController(IHostingEnvironment hostingEnvironment)
{
   _hostingEnvironment = hostingEnvironment;
}
public IActionResult RedactPDF()
{
string path = Path.Combine(_hostingEnvironment.ContentRootPath, "Data", "Input.pdf");
FileStream inputDocument = new FileStream(path, FileMode.Open);
//Load an existing PDF document.
PdfLoadedDocument loadedDocument = new PdfLoadedDocument(inputDocument);
//Get the first page from the document.
PdfLoadedPage page = loadedDocument.Pages[0] as PdfLoadedPage;
//Create a redaction object.
PdfRedaction redaction = new PdfRedaction(new RectangleF(343, 147, 60, 17), Color.Black);
//Add a redaction object into the redaction collection of the loaded page.
page.AddRedaction(redaction);
//Redact the contents from the PDF document.
loadedDocument.Redact();
//Save the PDF document.
MemoryStream stream = new MemoryStream();
//Save the PDF document.
loadedDocument.Save(stream);
stream.Position = 0;
//Close the document.
loadedDocument.Close(true);
//Download the PDF document in the browser.
FileStreamResult fileStreamResult = new FileStreamResult(stream, "application/pdf");
fileStreamResult.FileDownloadName = "RedactPDF.pdf";
return fileStreamResult;}

6. Build and run the application, the website will open in the browser, then, you can redact the content from a PDF document.

7. By executing the program, you will get the PDF document as follows.

A complete work sample for redact content from a PDF document can be downloaded from RedactionSample.zip.

Take a moment to peruse the documentation. You can find the other options like display text, image, and pattern on the redacted area, fill color on the redacted area. Also, redact the PDF without drawing the fill color, appearance, and features like encrypt and decrypt PDF document, and digitally sign a PDF file with code examples.

Refer to this link to explore a rich set of Syncfusion Essential® PDF features.

Also see:

Compress a PDF file in WinForms

Create a PDF file in Xamarin

Create a PDF file in ASP.NET MVC

Create a PDF file in WPF

Create a PDF file in Windows Forms

Note:

A new version of Essential Studio® for ASP.NET is available. Versions prior to the release of Essential Studio® 2014, Volume 2 will now be referred to as classic versions. The new ASP.NET suite is powered by Essential Studio for JavaScript, providing client-side rendering of HTML5-JavaScript controls, offering better performance, and better support for touch interactivity. The new version includes all the features of the old version, so migration is easy.

The Classic controls can be used in existing projects; however, if you are starting a new project, we recommend using the latest version of Essential Studio® for ASP.NET. Although Syncfusion® will continue to support all Classic Versions, we are happy to assist you in migrating to the newest edition.

For current customers, you can check out our components from the License and Downloads page. If you are new to Syncfusion®, you can try our 30-day free trial to check out our other controls. If you have any queries or require clarifications, please let us know in the comments section below.

You can also contact us through our support forums or feedback portal. We are always happy to assist you!