C#实现PDF签名时添加时间戳的2种方法(附VB.NET代码)

using Spire.Pdf;
using Spire.Pdf.Security;
using System.Drawing;

namespace TimeStamp
{
    class Program
    {
        static void Main(string[] args)
        {
            //加载PDF文档
            PdfDocument pdf = new PdfDocument();
            pdf.LoadFromFile("sample.pdf");

            //获取第2页
            PdfPageBase page = pdf.Pages[1];

            //加载数字证书（.pfx文件及秘钥）
            PdfCertificate cert = new PdfCertificate("test.pfx", "123456");

            //加载签名图片
            Spire.Pdf.Graphics.PdfImage image = Spire.Pdf.Graphics.PdfImage.FromFile("sign.png");

            //添加与图片大小相同的签名到第2页指定坐标位置
            PdfSignature signature = new PdfSignature(page.Document, page, cert, "sign1");//添加数字签名
            signature.Bounds = new RectangleF(new PointF(400,700), new SizeF(image.Width, image.Height));//设置签名的页面坐标位置、大小与图片相同
            signature.SignImageSource = image;
            signature.GraphicsMode = Spire.Pdf.Security.GraphicMode.SignImageAndSignDetail;//设置签名为图片模式
            signature.SignImageLayout = Spire.Pdf.Security.SignImageLayout.Stretch;
            signature.DocumentPermissions = Spire.Pdf.Security.PdfCertificationFlags.AllowFormFill | Spire.Pdf.Security.PdfCertificationFlags.AllowComments;//文档权限           

            //配置时间戳服务器，添加时间戳
            string url = "Your TimeStamp Server URL";
            signature.ConfigureTimestamp(url);
            //signature.ConfigureTimestamp(url, "Author", "123654");//添加时间戳时设置用户名和密码
            

            //保存文档
            pdf.SaveToFile("TimeStamp1.pdf",FileFormat.PDF);
            System.Diagnostics.Process.Start("TimeStamp1.pdf");
        }
    }
}

Imports Spire.Pdf
Imports Spire.Pdf.Security
Imports System.Drawing

Namespace TimeStamp
    Class Program
        Private Shared Sub Main(args As String())
            '加载PDF文档
            Dim pdf As New PdfDocument()
            pdf.LoadFromFile("sample.pdf")

            '获取第2页
            Dim page As PdfPageBase = pdf.Pages(1)

            '加载数字证书（.pfx文件及秘钥）
            Dim cert As New PdfCertificate("test.pfx", "123456")

            '加载签名图片
            Dim image As Spire.Pdf.Graphics.PdfImage = Spire.Pdf.Graphics.PdfImage.FromFile("sign.png")

            '添加与图片大小相同的签名到第2页指定坐标位置
            Dim signature As New PdfSignature(page.Document, page, cert, "sign1")

            '添加数字签名
            signature.Bounds = New RectangleF(New PointF(400, 700), New SizeF(image.Width, image.Height))

            '设置签名的页面坐标位置、大小与图片相同
            signature.SignImageSource = image
            signature.GraphicsMode = Spire.Pdf.Security.GraphicMode.SignImageAndSignDetail

            '设置签名为图片模式
            signature.SignImageLayout = Spire.Pdf.Security.SignImageLayout.Stretch
            signature.DocumentPermissions = Spire.Pdf.Security.PdfCertificationFlags.AllowFormFill Or Spire.Pdf.Security.PdfCertificationFlags.AllowComments'文档权限           

            '配置时间戳服务器，添加时间戳
            Dim url As String = "Your TimeStamp Server URL"
            signature.ConfigureTimestamp(url)
            'signature.ConfigureTimestamp(url, "Author", "123654");//添加时间戳时设置用户名和密码

            '保存文档
            pdf.SaveToFile("TimeStamp1.pdf", FileFormat.PDF)
            System.Diagnostics.Process.Start("TimeStamp1.pdf")
        End Sub
    End Class
End Namespace

using Spire.Pdf;
using Spire.Pdf.Graphics;
using Spire.Pdf.Interactive.DigitalSignatures;
using System.Drawing;
using System.Security.Cryptography.X509Certificates;

namespace TimeStamp2
{
    class Program
    {
        static void Main(string[] args)
        {
            //加载PDF文档
            PdfDocument doc = new PdfDocument();
            doc.LoadFromFile("sample.pdf");

            //加载pfx数字证书及秘钥
            X509Certificate2 x509 = new X509Certificate2("test.pfx", "123456");

            //实例化PdfPKCS7Formatter类的对象
            PdfPKCS7Formatter formatter = new PdfPKCS7Formatter(x509, false);
            formatter.TimestampService = new TSAHttpService("Your TimeStamp Server URL");//配置时间戳服务器

            //添加签名
            PdfOrdinarySignatureMaker signatureMaker = new PdfOrdinarySignatureMaker(doc, formatter);            
            IPdfSignatureAppearance signatureAppearance = new PdfCustomSignatureAppearance();
            signatureMaker.MakeSignature("sign", doc.Pages[1], 400, 650, 150, 80, signatureAppearance);
            
            //保存签名后的PDF文档
            doc.SaveToFile("TimeStamp2.pdf", FileFormat.PDF);
            System.Diagnostics.Process.Start("TimeStamp2.pdf");

        }
        public class PdfCustomSignatureAppearance : IPdfSignatureAppearance
        {
            public void Generate(PdfCanvas canvas)
            {
                PdfTrueTypeFont font = new PdfTrueTypeFont(new Font("Arial", 12), true);
                canvas.DrawString("SIGNED! A CLASS.\n By Tom Smith", font, PdfBrushes.Red, new PointF(0, 0));
            }
        }
    }
}

Imports Spire.Pdf
Imports Spire.Pdf.Graphics
Imports Spire.Pdf.Interactive.DigitalSignatures
Imports System.Drawing
Imports System.Security.Cryptography.X509Certificates

Namespace TimeStamp2
    Class Program
        Private Shared Sub Main(args As String())
            '加载PDF文档
            Dim doc As New PdfDocument()
            doc.LoadFromFile("sample.pdf")

            '加载pfx数字证书及秘钥
            Dim x509 As New X509Certificate2("test.pfx", "123456")

            '实例化PdfPKCS7Formatter类的对象
            Dim formatter As New PdfPKCS7Formatter(x509, False)
            formatter.TimestampService = New TSAHttpService("Your TimeStamp Server URL")
            '配置时间戳服务器
            
'添加签名
            Dim signatureMaker As New PdfOrdinarySignatureMaker(doc, formatter)
            Dim signatureAppearance As IPdfSignatureAppearance = New PdfCustomSignatureAppearance()
            signatureMaker.MakeSignature("sign", doc.Pages(1), 400, 650, 150, 80, _
                signatureAppearance)

            '保存签名后的PDF文档
            doc.SaveToFile("TimeStamp2.pdf", FileFormat.PDF)
            System.Diagnostics.Process.Start("TimeStamp2.pdf")

        End Sub
        Public Class PdfCustomSignatureAppearance
            Implements IPdfSignatureAppearance
            Public Sub Generate(canvas As PdfCanvas)
                Dim font As New PdfTrueTypeFont(New Font("Arial", 12), True)
                canvas.DrawString("SIGNED! A CLASS." & vbLf & " By Tom Smith", font, PdfBrushes.Red, New PointF(0, 0))
            End Sub
        End Class
    End Class
End Namespace