Where does LinkAnnotation live in the IronPDF API?

LinkAnnotation is in the IronPdf.Annotations namespace, shipped in IronPdf.dll. It derives from PdfClientAccessor.

What are the key properties of LinkAnnotation?

Properties commonly used on LinkAnnotation include AnnotationIndex, Color, Contents, DestinationBottom. Each property configures one aspect of the PDF annotations surface exposed by the class.

How do you create a LinkAnnotation in C#?

Instantiate LinkAnnotation directly with one of its constructors, or obtain it from the relevant IronPDF API entry point. The class supports the standard C# new expression where a constructor is defined.

Class LinkAnnotation

Q: What is the LinkAnnotation class used for in C#?

LinkAnnotation is the IronPDF class that creates a clickable link annotation that navigates to a specific page within the same PDF document. It is part of the IronPdf.Annotations namespace and is used through the IronPDF C# API.

Creates a clickable link annotation that navigates to a specific page within the same PDF document. Useful for building custom tables of contents, cross-references, and in-document navigation.

// Add a link on page 0 that navigates to page 5:
var link = new LinkAnnotation(pageIndex: 0, destinationPageIndex: 5)
{
    X = 50, Y = 700,
    Width = 200, Height = 20
};
pdf.Annotations.Add(link);

// Custom TOC link with color:
var tocLink = new LinkAnnotation(0, 3)
{
    X = 72, Y = 600,
    Width = 300, Height = 16,
    Contents = "Chapter 1 - Introduction"
};
pdf.Annotations.Add(tocLink);

The link annotation creates an invisible clickable region on the page.

See: https://ironpdf.com/how-to/annotations/

Coordinate note: The Y property sets the bottom edge

of the clickable area using PDF coordinates (origin at bottom-left of page). When positioning

links over existing text using PdfPage.TextChunks, use BoundingBox.Bottom for Y and Math.Abs(BoundingBox.Top - BoundingBox.Bottom) for Height.

Inheritance

System.Object

PdfClientAccessor

LinkAnnotation

Implements

IAnnotation

Namespace: IronPdf.Annotations

Assembly: IronPdf.dll

Syntax

public class LinkAnnotation : PdfClientAccessor, IAnnotation

Working with PDF annotations in IronPDF runs through LinkAnnotation. It creates a clickable link annotation that navigates to a specific page within the same PDF document.

LinkAnnotation matters when an application needs to configure or invoke PDF annotations from C# code. The class encapsulates the related options and behavior in a single object that is set up once and reused across render or processing calls. Typical scenarios include batch generation pipelines, templated document workflows, and integration with existing C# document services.

To use LinkAnnotation, instantiate or obtain it from the relevant entry point in the IronPDF C# API. Key properties include AnnotationIndex, Color, Contents, DestinationBottom. Assign options or invoke methods on the instance to configure or perform the operation. The annotations covers typical usage in C# end to end.

using IronPdf;

// Obtain LinkAnnotation from the relevant entry point in the IronPDF API
void Configure(LinkAnnotation instance)
{
    var current = instance.AnnotationIndex;
    instance.ToString();
}

For the broader workflow, see the color grayscale guide in the IronPDF C# documentation. For broader context, the PDF annotations portion of the IronPDF C# API contains related types that work with LinkAnnotation directly. LinkAnnotation instances inherit additional members from PdfClientAccessor that may be relevant in advanced scenarios. In application code, treat LinkAnnotation as a configured object that is constructed once and reused across operations rather than instantiated per call. Configuration is generally idempotent: assigning the same property value twice has the same effect as assigning it once. For diagnostic purposes, inspect the relevant LinkAnnotation property after each operation to confirm the configured state. See the constructors, properties, and methods tables below for the complete API surface of LinkAnnotation. Application code typically obtains or instantiates a single LinkAnnotation and shares it across multiple IronPDF operations rather than recreating it per call.

Constructors

LinkAnnotation(Int32, Int32)

Creates a link annotation on the specified page that navigates to a destination page. The annotation must be added to the document via Annotations.

Declaration

public LinkAnnotation(int pageIndex, int destinationPageIndex)

Parameters

Type	Name	Description
System.Int32	pageIndex	Zero-based index of the page where the link is placed.
System.Int32	destinationPageIndex	Zero-based index of the page to navigate to when clicked.

LinkAnnotation(Int32, Int32, String)

Creates a link annotation on the specified page that navigates to a destination page, with descriptive text for identification. The annotation must be added to the document via Annotations.

Declaration

public LinkAnnotation(int pageIndex, int destinationPageIndex, string contents)

Parameters

Type	Name	Description
System.Int32	pageIndex	Zero-based index of the page where the link is placed.
System.Int32	destinationPageIndex	Zero-based index of the page to navigate to when clicked.
System.String	contents	Descriptive text for the link annotation.

Properties

AnnotationIndex

Annotation index (of a given page)

Declaration

public int AnnotationIndex { get; set; }

Property Value

Type	Description
System.Int32

Color

Gets or sets the color of the link annotation border.

Declaration

public Color Color { get; set; }

Property Value

Type	Description
IronSoftware.Drawing.Color

Gets or sets the descriptive text content for this link annotation.

Declaration

public string Contents { get; set; }

Property Value

Type	Description
System.String

DestinationBottom

Gets or sets the bottom coordinate of the destination position, in points. Used by PageRect.

Declaration

public int DestinationBottom { get; set; }

Property Value

Type	Description
System.Int32

DestinationLeft

Gets or sets the left coordinate of the destination position, in points. Used by PageZoom, PageX, PageRect, and PageBoundsX.

Declaration

public int DestinationLeft { get; set; }

Property Value

Type	Description
System.Int32

DestinationPageIndex

Gets or sets the zero-based page index to navigate to when this link is clicked. Page 1 = index 0, Page 2 = index 1, etc.

Declaration

public int DestinationPageIndex { get; set; }

Property Value

Type	Description
System.Int32	Zero-based destination page index.

DestinationRight

Gets or sets the right coordinate of the destination position, in points. Used by PageRect.

Declaration

public int DestinationRight { get; set; }

Property Value

Type	Description
System.Int32

DestinationTop

Gets or sets the top coordinate of the destination position, in points. Used by PageZoom, PageY, PageRect, and PageBoundsY.

Declaration

public int DestinationTop { get; set; }

Property Value

Type	Description
System.Int32

DestinationType

Gets or sets the destination type that controls how the page is displayed when the link is clicked. Default is Page which fits the entire destination page in the window. Use PageY with DestinationTop to scroll to a specific vertical position, or PageZoom for full control over position and zoom.

Declaration

public BookmarkDestinations DestinationType { get; set; }

Property Value

Type	Description
BookmarkDestinations	Destination type (default: Page).

DestinationZoom

Gets or sets the zoom level (in percent) for the destination. Used by PageZoom. A value of 0 means inherit the current zoom.

Declaration

public int DestinationZoom { get; set; }

Property Value

Type	Description
System.Int32

Height

Gets or sets the height of the clickable link area, in points.

Declaration

public int Height { get; set; }

Property Value

Type	Description
System.Int32

Hidden

Gets or sets whether the link annotation is hidden from users.

Declaration

public bool Hidden { get; set; }

Property Value

Type	Description
System.Boolean

PageIndex

Gets or sets the zero-based page index where this link annotation is placed. Page 1 = index 0, Page 2 = index 1, etc. (default: 0 - first page).

Declaration

public int PageIndex { get; set; }

Property Value

Type	Description
System.Int32	Zero-based page index (default: 0).

Rectangle

Gets or sets the position and size of the clickable link area.

Declaration

public Rectangle Rectangle { get; set; }

Property Value

Type	Description
IronSoftware.Drawing.Rectangle

Title

Gets or sets the title of the link annotation.

Declaration

public string Title { get; set; }

Property Value

Type	Description
System.String

Width

Gets or sets the width of the clickable link area, in points.

Declaration

public int Width { get; set; }

Property Value

Type	Description
System.Int32

X

Gets or sets the horizontal X position from the LEFT edge of the page, in points. 72 points = 1 inch.

When using BoundingBox from text extraction: Use BoundingBox.Left for this value.

Declaration

public int X { get; set; }

Property Value

Type	Description
System.Int32	Horizontal position in points from left edge (default: -1 if not set).

Y

Gets or sets the vertical Y position from the BOTTOM edge of the page, in points. 72 points = 1 inch. PDF coordinate system places Y=0 at bottom of page.

When using BoundingBox from text extraction: Use BoundingBox.Bottom (not BoundingBox.Top) for this value, since Y defines the bottom edge of the clickable area and BoundingBox uses the same PDF coordinate system.

var box = textChunk.BoundingBox;
link.Y = (int)box.Bottom;       // correct â€” aligns with text
link.Height = (int)Math.Abs(box.Top - box.Bottom);
// link.Y = (int)box.Top;       // wrong â€” places link above the text

Declaration

public int Y { get; set; }

Property Value

Type	Description
System.Int32	Vertical position in points from bottom edge (default: -1 if not set).

Methods

ToString()

Returns a System.String that represents this link annotation.

Declaration

public override string ToString()

Returns

Type	Description
System.String

Implements

IAnnotation