How to create accessible PDF file in C#, VB.NET?
A PDF file without accessible information is of no use to the people who need a screen reader and text-to-speech tool. Therefore, a need for creating accessible PDF files (usually referred to as a tagged PDFs) arises.
Tagged PDF
The tagged PDF is a PDF file that includes structure in terms of tags that defines reading order and the meaning of significant elements such as figures, images, lists, tables. PDF tags provide a hidden-structured, textual representation of the PDF content that is presented to the screen readers. They exist only for accessibility purposes and have no visible effect on the PDF file.
Syncfusion Essential PDF is a .NET PDF library used to create, read, and edit PDF documents. Using this library, you can create accessible PDF document easily in C# and VB.NET.
Steps to create accessible PDF programmatically:
- Create a new C# console application project.
- Install the Syncfusion.Pdf.WinForms NuGet package as reference to your .NET Framework application from NuGet.org.
- Include the following namespace in the Program.cs file.
C#
using Syncfusion.Pdf; using Syncfusion.Pdf.Graphics; using System.Drawing;
VB.NET
Imports Syncfusion.Pdf Imports Syncfusion.Pdf.Graphics Imports System.Drawing
- Use the following code snippet to create tagged PDF or PDF/UA with auto-tag feature, which enables all the elements in the document is tagged with appropriate tag type that is paragraph, figure, annotation and more.
C#
//Creates new PDF document
PdfDocument document = new PdfDocument();
//Set true to auto tag all elements in document
document.AutoTag = true;
document.DocumentInformation.Title = "AutoTag";
// Add a new page to the document
PdfPage page = document.Pages.Add();
//Creates new text element
PdfTextElement element = new PdfTextElement("This is paragraph ONE.", new PdfStandardFont(PdfFontFamily.Helvetica, 12));
element.Brush = new PdfSolidBrush(new PdfColor(89, 89, 93));
element.Draw(page, new RectangleF(0, 0, page.Graphics.ClientSize.Width / 2, 200));
//Creates new text element
PdfTextElement element1 = new PdfTextElement("This is paragraph TWO.", new PdfStandardFont(PdfFontFamily.Helvetica, 12));
element1.Brush = new PdfSolidBrush(new PdfColor(89, 89, 93));
element1.Draw(page, new RectangleF(0, 50, page.Graphics.ClientSize.Width / 2, 200));
//Creates new text element
PdfTextElement element2 = new PdfTextElement("This is paragraph THREE.", new PdfStandardFont(PdfFontFamily.Helvetica, 12));
element2.Brush = new PdfSolidBrush(new PdfColor(89, 89, 93));
element2.Draw(page.Graphics, new PointF(0, 100));
//Save the document
document.Save("AutoTag.pdf");
//Close the document
document.Close(true);
//This will open the PDF file so, the result will be seen in default PDF viewer
Process.Start("AutoTag.pdf");
VB.NET
'Creates new PDF document
Dim document As New PdfDocument()
'Set true to auto tag all elements in document
document.AutoTag = True
document.DocumentInformation.Title = "AutoTag"
'Add a new page to the document
Dim page As PdfPage = document.Pages.Add()
'Creates new text element
Dim element As New PdfTextElement("This is paragraph ONE.", New PdfStandardFont(PdfFontFamily.Helvetica, 12))
element.Brush = New PdfSolidBrush(New PdfColor(89, 89, 93))
element.Draw(page, New RectangleF(0, 0, page.Graphics.ClientSize.Width / 2, 200))
'Creates new text element
Dim element1 As New PdfTextElement("This is paragraph TWO.", New PdfStandardFont(PdfFontFamily.Helvetica, 12))
element1.Brush = New PdfSolidBrush(New PdfColor(89, 89, 93))
element1.Draw(page, New RectangleF(0, 50, page.Graphics.ClientSize.Width / 2, 200))
'Creates new text element
Dim element2 As New PdfTextElement("This is paragraph THREE.", New PdfStandardFont(PdfFontFamily.Helvetica, 12))
element2.Brush = New PdfSolidBrush(New PdfColor(89, 89, 93))
element2.Draw(page.Graphics, New PointF(0, 100))
'Save the document
document.Save("AutoTag.pdf")
'Close the document
document.Close(True)
'This will open the PDF file so, the result will be seen in default PDF viewer
Process.Start("AutoTag.pdf")
Download the work sample from CreateAccessiblePDF.Zip
By executing the program, you will get the PDF document as follows. 
Take a moment to peruse the documentation, where you will find other options like adding tag to text element, image, shapes, form fields, annotation, hyperlink, template, table and list element with code examples.
Refer here to explore the rich set of Syncfusion Essential PDF features.
An online sample link to create tagged PDF or accessible PDF using auto tag feature.
Starting with v16.2.0.x, if you reference Syncfusion assemblies from trial setup or from the NuGet feed, include a license key in your projects. Refer to link to learn about generating and registering Syncfusion license key in your application to use the components without trail message.
