How to add digital signature in exsiting signature field with WinForms PDF?

How to add a digital signature to an existing signature field in a document:

It is possible to digitally sign an existing signature field. For this, you need to pass the signature field information and certificate details to the PdfSignature class. Below is the code snippet.

C#:

// Load the Certificate
PdfCertificate pdfCert = new PdfCertificate(@"../../Data/PDF.pfx", "syncfusion");

// Load an existing Pdf document
PdfLoadedDocument doc = new PdfLoadedDocument("../../Data/emptypdf_modified.pdf");

// Get the signature field to be digitally signed
PdfLoadedSignatureField f = doc.Form.Fields["Firma1"] as PdfLoadedSignatureField;

// Pass the signature field and certificate information to the PdfSignature class; this will digitally sign the existing signature field
PdfSignature signature = new PdfSignature(doc, f.Page, pdfCert, f.Name, f);

// Save the document and dispose of it
doc.Save("signed1.pdf");
doc.Close(true);

Sample Link:

http://www.syncfusion.com/downloads/support/directtrac/141714/ze/SignSIgnatureField445227762

Take a moment to peruse the documentation. You can find options like adding an ordered or unordered list in a PDF document. The styles can be bullet, circle, or image.

Note:

Starting with v16.2.0.x, if you reference Syncfusion® assemblies from the trial setup or the NuGet feed, include a license key in your projects. Refer to the link to learn about generating and registering the Syncfusion® license key in your application to use the components without a trial message.

Conclusion:

I hope you enjoyed learning about how to add digital signature in existing signature field with WinForms PDF.

You can refer to our Flutter PDF feature tour page to learn about its other groundbreaking feature representations and documentation, and how to quickly get started with configuration specifications. You can also explore our Flutter PDF Flutter PDF example to understand how to create and manipulate data.

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