What implements IAnnotation in IronPDF?

Concrete implementors of IAnnotation in IronPDF include LinkAnnotation, TextAnnotation. Code that accepts IAnnotation works uniformly across all implementors, with a cast to the concrete type only required when type-specific behavior is needed.

How do you use IAnnotation in C# code?

Accept IAnnotation as a parameter or return type in C# code that needs to work uniformly across IronPDF implementors. The interface defines the contract; concrete behavior is provided by the implementor returned at runtime.

What is the difference between IAnnotation and a concrete implementor?

IAnnotation is the interface contract; its concrete implementors carry the actual behavior. Reference IAnnotation when writing code that should work across multiple implementors; use a concrete type when a single implementor's behavior is required.

Where does IAnnotation live in the IronPDF API?

IAnnotation is in the IronPdf.Annotations namespace, shipped in IronPdf.dll. Concrete classes such as LinkAnnotation, TextAnnotation implement it.

Interface IAnnotation

PDF document annotation

Namespace: IronPdf.Annotations

Assembly: IronPdf.dll

Syntax

public interface IAnnotation

IAnnotation is the contract IronPDF C# code works through for PDF annotations. It represents PDF document annotation, so code can work with PDF annotations uniformly across implementors rather than binding to a concrete type.

Concrete implementors include LinkAnnotation, TextAnnotation. Code that accepts IAnnotation works uniformly across these implementors, so applications can read or configure C# PDF features without binding to a specific concrete type.

Most of the usable surface is inherited. The members that carry everyday use of this contract are AnnotationIndex, Color, Contents, DocumentId; consult these first when implementing or consuming IAnnotation.

using IronPdf;

// IAnnotation is consumed as the API surface for the family of implementors
void Consume(IAnnotation target)
{
    // Use members defined on the interface; concrete behavior follows the implementor
}

For collection-wide operations and end-to-end examples, see the IronPDF C# documentation for related guides. For collection-wide operations on IAnnotation instances, the IronPDF C# documentation lists the relevant container types and their methods. Concrete behavior depends on which implementor of IAnnotation is returned at runtime; consult the specific class reference for type-specific members. Polymorphic access through IAnnotation lets code work uniformly across the family of implementors, with a cast required only when type-specific behavior is needed. The reference tables below list the full set of members defined on IAnnotation along with any inherited members exposed through the contract. In a typical IronPDF C# workflow, IAnnotation appears as a parameter or return type at the boundary between the application and the IronPDF API. See the methods table below for the complete set of members defined directly on IAnnotation. Implementing IAnnotation directly in application code is uncommon; the typical pattern is to consume instances returned from the IronPDF API. When iterating over a collection of IAnnotation instances, prefer the inherited members for portable code; downcast only when type-specific behavior is required.

Properties

AnnotationIndex

Annotation index (of a given page)

Declaration

int AnnotationIndex { get; set; }

Property Value

Type	Description
System.Int32

Color

Annotation color

Declaration

Color Color { get; set; }

Property Value

Type	Description
IronSoftware.Drawing.Color

Annotation contents

Declaration

string Contents { get; set; }

Property Value

Type	Description
System.String

DocumentId

Document identifier

Declaration

IDocumentId DocumentId { get; set; }

Property Value

Type	Description
IronSoftware.Abstractions.Pdf.IDocumentId

Height

Annotation height

Declaration

int Height { get; set; }

Property Value

Type	Description
System.Int32

Hidden

Annotation visibility status

Declaration

bool Hidden { get; set; }

Property Value

Type	Description
System.Boolean

PageIndex

Page index

Declaration

int PageIndex { get; }

Property Value

Type	Description
System.Int32

Rectangle

Declaration

Rectangle Rectangle { get; set; }

Property Value

Type	Description
IronSoftware.Drawing.Rectangle

Title

Annotation title

Declaration

string Title { get; set; }

Property Value

Type	Description
System.String

Width

Annotation width

Declaration

int Width { get; set; }

Property Value

Type	Description
System.Int32

X

Annotation X position

Declaration

int X { get; set; }

Property Value

Type	Description
System.Int32

Y

Annotation y position

Declaration

int Y { get; set; }

Property Value

Type	Description
System.Int32