New to Telerik Document Processing? Start a free 30-day trial
SignatureField
Updated on Jun 3, 2026
The SignatureField class corresponds to the FormFieldType.Signature enum value and represents a placeholder that preserves digital signature information. It represents a form field that stores digital signature data. Use it to sign PDF documents or validate existing signatures.
To use the signing functionality in RadPdfProcessing for .NET Standard/.NET Core, you must add a reference to the
System.Security.Cryptography.PkcsNuGet package, version 9.0.9 or later. This functionality is available starting with R1 2022 SP1.
Properties
The SignatureField class provides the following properties:
| Property | Description |
|---|---|
Signature | Gets or sets the Signature value. Setting this property signs the document during export. Signing with multiple signatures is not supported. To validate a signature, use the Validate() and TryValidate() methods. Validation requires that the source stream is open and is performed against the document state at import time. See Digital Signature for more details. |
Widgets | The collection of Widget annotations representing the field on the PDF pages. Widgets can be added using AddWidget() and removed using Remove(). Implements IEnumerable. |
Example 1: Create a SignatureField and Add It to a Page
C#
RadFixedDocument document = new RadFixedDocument();
X509Certificate2 certificate = new X509Certificate2("JohnDoe.pfx", "johndoe");
SignatureField signatureField = new SignatureField("SampleSignature");
signatureField.Signature = new Signature(certificate); // The Signature property fo SignatureField is not available in PdfProcessing for .NET Standard.
SignatureWidget widget = signatureField.Widgets.AddWidget();
widget.Rect = new Rect(200, 600, 100, 100);
widget.Border = new AnnotationBorder(5, AnnotationBorderStyle.Solid, null);
//Create a Form object to define the appearance you would like for the signature field.
Telerik.Windows.Documents.Fixed.Model.Objects.Form form = new Telerik.Windows.Documents.Fixed.Model.Objects.Form();
form.FormSource = new FormSource();
form.FormSource.Size = new Size(120, 120);
FixedContentEditor formEditor = new FixedContentEditor(form.FormSource);
formEditor.DrawCircle(new Point(50, 50), 20);
formEditor.DrawText("Sample Signature");
//Add the FormSource object to the widget of the field.
widget.Content.NormalContentSource = form.FormSource;
RadFixedPage page = document.Pages.Last();
page.Annotations.Add(widget);
document.AcroForm.FormFields.Add(signatureField);