Create PDF marked content in C# and VB.NET

Marked content is PDF content that is either adjacent to (if the mark type is Point) or surrounded by (if the mark type is Start and End) PdfContentMark elements.

The PdfContentMark element specifies a tag that indicates the role or significance of the marked content, and, optionally, the properties of the marked content.

With the following example, you can learn how to mark geometrical content, which is a visual representation of specific Unicode content.

PDF marked content created with GemBox.Pdf C#/VB.NET library — Screenshot of PDF marked content created with GemBox.Pdf library

C#
VB.NET

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using GemBox.Pdf;
using GemBox.Pdf.Content.Marked;
using GemBox.Pdf.Objects;

class Program
{
    static void Main()
    {
        // If using the Professional version, put your serial key below.
        ComponentInfo.SetLicense("FREE-LIMITED-KEY");

        using (var document = new PdfDocument())
        {
            var page = document.Pages.Add();

            // Surround the path with the marked content start and marked content end elements.
            var markStart = page.Content.Elements.AddMarkStart(new PdfContentMarkTag(PdfContentMarkTagRole.Span));
            
            var markedProperties = markStart.GetEditableProperties().GetDictionary();

            // Set replacement text for a path, as specified in https://opensource.adobe.com/dc-acrobat-sdk-docs/standards/pdfstandards/pdf/PDF32000_2008.pdf#page=623
            markedProperties[PdfName.Create("ActualText")] = PdfString.Create("H");

            // Add the path that is a visual representation of the letter 'H'.
            var path = page.Content.Elements.AddPath()
                .BeginSubpath(100, 600).LineTo(100, 800)
                .BeginSubpath(100, 700).LineTo(200, 700)
                .BeginSubpath(200, 600).LineTo(200, 800);

            var format = path.Format;
            format.Stroke.IsApplied = true;
            format.Stroke.Width = 10;

            page.Content.Elements.AddMarkEnd();

            document.Save("MarkedContent.pdf");
        }
    }
}

Imports GemBox.Pdf
Imports GemBox.Pdf.Content.Marked
Imports GemBox.Pdf.Objects

Module Program

    Sub Main()

        ' If using the Professional version, put your serial key below.
        ComponentInfo.SetLicense("FREE-LIMITED-KEY")

        Using document = New PdfDocument()

            Dim page = document.Pages.Add()

            ' Surround the path with the marked content start and marked content end elements.
            Dim markStart = page.Content.Elements.AddMarkStart(New PdfContentMarkTag(PdfContentMarkTagRole.Span))

            Dim markedProperties = markStart.GetEditableProperties().GetDictionary()

            ' Set replacement text for a path, as specified in https://opensource.adobe.com/dc-acrobat-sdk-docs/standards/pdfstandards/pdf/PDF32000_2008.pdf#page=623
            markedProperties(PdfName.Create("ActualText")) = PdfString.Create("H")

            ' Add the path that is a visual representation of the letter 'H'.
            Dim path = page.Content.Elements.AddPath() _
                .BeginSubpath(100, 600).LineTo(100, 800) _
                .BeginSubpath(100, 700).LineTo(200, 700) _
                .BeginSubpath(200, 600).LineTo(200, 800)

            Dim format = path.Format
            format.Stroke.IsApplied = True
            format.Stroke.Width = 10

            page.Content.Elements.AddMarkEnd()

            document.Save("MarkedContent.pdf")
        End Using
    End Sub
End Module

Next steps

GemBox.Pdf is a .NET component that enables developers to read, merge and split PDF files or execute low-level object manipulations from .NET applications in a simple and efficient way.

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Published: April 23, 2021 | Modified: May 15, 2023 | Author: Stipo Rubic

Create PDF marked content in C# and VB.NET

See also

Next steps