Class CheckboxFormField

Inheritance
System.Object
CheckboxFormField
Implements
IronSoftware.Abstractions.Pdf.IPdfDocumentObject
IronSoftware.Abstractions.IDocumentObject
Namespace: IronSoftware.Forms
Assembly: IronPdf.dll
Syntax
public class CheckboxFormField : Object, ICheckableFormField, IFormField, IFormFieldObject, IFormFieldAnnotationObject, IPdfDocumentObject

PDF forms in IronPDF is handled through CheckboxFormField. It is part of the IronPDF PDF forms API.

CheckboxFormField 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 CheckboxFormField, instantiate or obtain it from the relevant entry point in the IronPDF C# API. Key properties include Annotations, Choices, Client, DefaultAppearance. Assign options or invoke methods on the instance to configure or perform the operation. The create forms covers typical usage in C# end to end.

using IronPdf;

// Obtain CheckboxFormField from the relevant entry point in the IronPDF API
void Configure(CheckboxFormField instance)
{
    var current = instance.Annotations;
    instance.Clear();
}

For the broader workflow, see the edit forms guide in the IronPDF C# documentation. For broader context, the PDF forms portion of the IronPDF C# API contains related types that work with CheckboxFormField directly. CheckboxFormField exposes additional members beyond those highlighted above; the reference tables on this page list the full set. In application code, treat CheckboxFormField 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 CheckboxFormField property after each operation to confirm the configured state. See the constructors, properties, and methods tables below for the complete API surface of CheckboxFormField. Application code typically obtains or instantiates a single CheckboxFormField and shares it across multiple IronPDF operations rather than recreating it per call.

Constructors

CheckboxFormField(String, String, UInt32, Double, Double, Double, Double)

Create a new checkbox form field using the specified parameters

Declaration
public CheckboxFormField(string name, string value, uint page_index, double x, double y, double width, double height)
Parameters
Type Name Description
System.String name

Form name
System.String value

Form value
System.UInt32 page_index

Form page index
System.Double x

Form x-coordinate
System.Double y

Form y-coordinate
System.Double width

Form width
System.Double height

Form height

Fields

OffValue

Value which can be assigned to a checkbox to disable it

Declaration
public static string OffValue
Field Value
Type Description
System.String

Properties

Annotations

Form field annotations

Declaration
public List<IFormFieldAnnotation> Annotations { get; protected set; }
Property Value
Type Description
System.Collections.Generic.List<IFormFieldAnnotation>

Choices

Selection choices

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

Client

Pdf client

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

DefaultAppearance

Default appearance string

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

DocumentId

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

FormFlags

Form field flags

Declaration
public PdfFormFieldFlags FormFlags { get; set; }
Property Value
Type Description
PdfFormFieldFlags

FormType

Form type

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

FullName

Fully qualified name

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

Height

Annotation height

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

MaxLength

Maximum number of characters which can be specified in the value

Declaration
public int MaxLength { get; set; }
Property Value
Type Description
System.Int32

Name

Partial name

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

ObjNum

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

ObjType

Object type

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

PageIndex

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

ReadOnly

True if read-only

Declaration
public bool ReadOnly { get; set; }
Property Value
Type Description
System.Boolean

RichText

Form value using rich text

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

SelectedIndex

Currently selected index

Declaration
public int SelectedIndex { get; set; }
Property Value
Type Description
System.Int32

Type

Pdf form field type

Declaration
public PdfFormFieldType Type { get; }
Property Value
Type Description
PdfFormFieldType

Value

Form value

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

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

Methods

Clear()

Clear any and all selected values

Declaration
public void Clear()

Select(Int32)

Select the value at the specified index

If no index is provided, selects the first value. If there are more than one options, throws an exception

Declaration
public string Select(int Index = -1)
Parameters
Type Name Description
System.Int32 Index
Returns
Type Description
System.String

Value at the selected index
Exceptions
Type Condition
System.Exception

No index was provided and there is more than one selectable option

SetDefaultFont(String, Int32, Color)

Set the default font to be used by this form field and any associated annotations

Declaration
public void SetDefaultFont(string FontName, int FontSize, Color FontColor)
Parameters
Type Name Description
System.String FontName

Font name with weight. Example "AdobeThai-Bold"
System.Int32 FontSize

Font size (whole integer such as 12 or 24)
System.Drawing.Color FontColor

Font color (only R, G, and B are used)
Remarks

This option may be overwritten by fonts applied to specific form field annotations

Implements

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