Create Visible Digital Signature in PDF in C#

 Digital Signature is widely used to protect the PDF files and it is so important that we always try our best to improve our Spire.PDF better and better. Besides the previous method of creating digital signature in PDF, Spire.PDF now supports to create visible digital signature in PDF with C# code.

Make sure Spire.PDF for .NET (version 2.9 or above) has been installed correctly. Add Spire.PDF.dll as reference in the downloaded Bin folder through the below path: "...\Spire.PDF\Bin\NET4.0\ Spire.PDF.dll".

01	using Spire.Pdf;

02	using Spire.Pdf.Graphics;

03	using Spire.Pdf.Security;

04	using System;

05	using System.Drawing;

06

07	namespace DigitalSignature

08

{

09	class Program

10

{

11	static void Main(string[] args)

12

{

13	//load a pdf document

14	PdfDocument doc = new PdfDocument();

15	doc.LoadFromFile(@"C:\Users\Administrator\Desktop\test.pdf");

16

17	//load the certificate

18	PdfCertificate cert = new PdfCertificate(@"C:\Users\Administrator\Desktop\gary.pfx", "e-iceblue");

19

20	//initialize a PdfSignature instance

21	PdfSignature signature = new PdfSignature(doc, doc.Pages[0], cert, "Signature1");

22

23	//set the signature location

24	signature.Bounds = new RectangleF(new PointF(200, 200), new SizeF(200, 90));

25

26	//set the image of signature

27	signature.SignImageSource = PdfImage.FromFile(@"C:\Users\Administrator\Desktop\E-iceblueLogo.png");

28

29	//set the content of signature

30	signature.GraphicsMode = GraphicMode.SignImageAndSignDetail;

31	signature.NameLabel = "Signer:";

32	signature.Name = "Gary";

33	signature.ContactInfoLabel = "ContactInfo:";

34	signature.ContactInfo = signature.Certificate.GetNameInfo(System.Security.Cryptography.X509Certificates.X509NameType.SimpleName, true);

35	signature.DistinguishedNameLabel = "DN: ";

36	signature.DistinguishedName = signature.Certificate.IssuerName.Name;

37	signature.LocationInfoLabel = "Location:";

38	signature.LocationInfo = "Chengdu";

39	signature.ReasonLabel = "Reason: ";

40	signature.Reason = "Le document est certifie";

41	signature.DateLabel = "Date:";

42	signature.Date = DateTime.Now;

43	signature.DocumentPermissions = PdfCertificationFlags.AllowFormFill | PdfCertificationFlags.ForbidChanges;

44	signature.Certificated = true;

45

46	//set fonts

47	signature.SignDetailsFont = new PdfFont(PdfFontFamily.TimesRoman, 10f);

48	signature.SignNameFont = new PdfFont(PdfFontFamily.Courier, 15);

49

50	//set the sign image layout mode

51	signature.SignImageLayout = SignImageLayout.None;

52

53	//save the file

54	doc.SaveToFile("signature.pdf");

55

}

56

}

57

}