Class FormFieldAnnotation

Document form field annotation

Inheritance
System.Object
FormFieldAnnotation
Implements
IronSoftware.Abstractions.Pdf.IPdfDocumentObject
IronSoftware.Abstractions.IDocumentObject
Namespace: IronSoftware.Forms
Assembly: IronPdf.dll
Syntax
public class FormFieldAnnotation : Object, IFormFieldAnnotation, IFormFieldAnnotationObject, IPdfDocumentObject

Use FormFieldAnnotation in IronPDF when a C# application works with PDF forms. It represents document form field annotation.

FormFieldAnnotation matters when an application needs to configure or invoke PDF forms 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 FormFieldAnnotation, instantiate or obtain it from the relevant entry point in the IronPDF C# API. Key properties include AnnotationFlags, Appearances, AppearanceState, Client. Assign options or invoke methods on the instance to configure or perform the operation.

using IronPdf;

var instance = new FormFieldAnnotation();
var current = instance.AnnotationFlags;
// Read or assign other properties such as Appearances, AppearanceState

For the broader workflow, see the IronPDF C# documentation for related how-to guides and examples. For broader context, the PDF forms portion of the IronPDF C# API contains related types that work with FormFieldAnnotation directly. FormFieldAnnotation exposes additional members beyond those highlighted above; the reference tables on this page list the full set. In application code, treat FormFieldAnnotation 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 FormFieldAnnotation property after each operation to confirm the configured state. See the constructors, properties, and methods tables below for the complete API surface of FormFieldAnnotation. Application code typically obtains or instantiates a single FormFieldAnnotation and shares it across multiple IronPDF operations rather than recreating it per call. For multi-threaded scenarios, follow the threading guidance for the relevant IronPDF entry point; FormFieldAnnotation instances are not assumed to be thread-safe unless documented.

Constructors

FormFieldAnnotation()

Create a new form field annotation

Declaration
public FormFieldAnnotation()

Properties

AnnotationFlags

Annotation flags

Declaration
public PdfAnnotationFlags AnnotationFlags { get; set; }
Property Value
Type Description
PdfAnnotationFlags

Appearances

Annotation appearance names

Declaration
public List<string> Appearances { get; protected set; }
Property Value
Type Description
System.Collections.Generic.List<System.String>

AppearanceState

Current active appearance

Declaration
public string AppearanceState { get; set; }
Property Value
Type Description
System.String

Client

Pdf client

Declaration
public IPdfClient Client { get; set; }
Property Value
Type Description
IronSoftware.Pdfium.IPdfClient

DocumentId

Declaration
public IDocumentId DocumentId { get; set; }
Property Value
Type Description
IronSoftware.Abstractions.Pdf.IDocumentId

FormField

Parent form

Declaration
public IFormFieldObject FormField { get; set; }
Property Value
Type Description
IFormFieldObject

Height

Annotation height

Declaration
public double Height { get; set; }
Property Value
Type Description
System.Double

Javascript

Javascript to execute when the annotation is interacted with

Declaration
public string Javascript { get; set; }
Property Value
Type Description
System.String
Remarks

See ISO 21757-1:2020 for an ECMAScript reference

ObjNum

Declaration
public uint ObjNum { get; set; }
Property Value
Type Description
System.UInt32

OnAppearance

Name of the appearance which is active when this annotation is selected

Declaration
public string OnAppearance { get; set; }
Property Value
Type Description
System.String

PageIndex

Declaration
public uint PageIndex { get; set; }
Property Value
Type Description
System.UInt32

Width

Annotation width

Declaration
public double Width { get; set; }
Property Value
Type Description
System.Double

X

Annotation X position

Declaration
public double X { get; set; }
Property Value
Type Description
System.Double

Y

Annotation y position

Declaration
public double Y { get; set; }
Property Value
Type Description
System.Double

Implements

IronSoftware.Abstractions.Pdf.IPdfDocumentObject
IronSoftware.Abstractions.IDocumentObject