Interface IFormField

Form field object with embedded annotation

Inherited Members
Namespace: IronSoftware.Forms
Assembly: IronPdf.dll
Syntax
public interface IFormField : IFormFieldObject, IFormFieldAnnotationObject, IPdfDocumentObject

When a PDF form field needs its default text appearance adjusted at runtime, IFormField is the contract that makes it possible. The interface extends IFormFieldObject and represents a form field with an embedded annotation, exposing SetDefaultFont so calling code can assign a font name, size, and color without depending on a concrete field type. Any object that implements IFormField can accept that call, keeping rendering logic decoupled from the specific field variant (text box, combo box, and so on).

SetDefaultFont(string FontName, int FontSize, Color FontColor) is the single declared member. It writes the appearance characteristics into the field's embedded annotation, so the chosen font is reflected both when the PDF is rendered on screen and when it is printed. The FontName parameter accepts a standard PDF font name or an embedded font identifier, FontSize sets the point size, and FontColor controls the text color using a System.Drawing.Color value.

Typical usage retrieves an IFormField reference from IronPDF's form-field collection on a loaded PdfDocument, then calls SetDefaultFont before saving. Coding against the interface rather than a concrete type means the same helper method can style every field in a mixed form without a type switch.

Explore related capabilities through the IronPDF PDF forms how-to and the IronPDF examples library.

Methods

SetDefaultFont(String, Int32, Color)

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

Declaration
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

Inherited members

Annotations
Choices
DefaultAppearance
FormFlags
FormType
FullName
MaxLength
Name
ObjType
ReadOnly
RichText
Type
Value
X
Y
Width
Height
Client