VisualSignature.cs
 // // This code is part of Document Solutions for PDF demos. // Copyright (c) MESCIUS inc. All rights reserved. // using System; using System.IO; using System.Drawing; using GrapeCity.Documents.Pdf; using GrapeCity.Documents.Pdf.AcroForms; using GrapeCity.Documents.Text; using GrapeCity.Documents.Drawing; using System.Security.Cryptography.X509Certificates; using GCTEXT = GrapeCity.Documents.Text; using GCDRAW = GrapeCity.Documents.Drawing; namespace DsPdfWeb.Demos { // This sample demonstrates how to create and sign a PDF with a .pfx file, // using a SignatureField and a signature image. // The sample then loads the signed file back into another GcPdfDocument instance // and verifies the signature. // This sample is identical to SignDoc, but adds an image representing the signature. public class VisualSignature { public int CreatePDF(Stream stream) { var doc = new GcPdfDocument(); var page = doc.NewPage(); var tf = new TextFormat() { Font = StandardFonts.Times, FontSize = 14 }; page.Graphics.DrawString("Hello, World!\n" + "Signed by DsPdfWeb VisualSignature sample.", tf, new PointF(72, 72)); // Init a test certificate: var pfxPath = Path.Combine("Resources", "Misc", "DsPdfTest.pfx"); var cert = new X509Certificate2(File.ReadAllBytes(pfxPath), "qq", X509KeyStorageFlags.MachineKeySet | X509KeyStorageFlags.PersistKeySet | X509KeyStorageFlags.Exportable); var sp = new SignatureProperties() { SignatureBuilder = new Pkcs7SignatureBuilder() { CertificateChain = new X509Certificate2[] { cert } }, Location = "DsPdfWeb Demo Browser", SignerName = "DsPdfWeb", }; // Add an image representing the signature: sp.SignatureAppearance.Image = GCDRAW.Image.FromFile(Path.Combine("Resources", "ImagesBis", "signature.png")); sp.SignatureAppearance.CaptionImageRelation = GrapeCity.Documents.Pdf.Annotations.CaptionImageRelation.ImageOnly; // Init a signature field to hold the signature: var sf = new SignatureField(); sf.Widget.Rect = new RectangleF(72, 72 * 2, 72 * 4, 36); sf.Widget.Page = page; sf.Widget.BackColor = Color.LightSeaGreen; sf.Widget.DefaultAppearance.Font = StandardFonts.Helvetica; sf.Widget.ButtonAppearance.Caption = $"Signer: {sp.SignerName}\r\nLocation: {sp.Location}"; // Add the signature field to the document: doc.AcroForm.Fields.Add(sf); // Connect the signature field and signature props: sp.SignatureField = sf; // Sign and save the document: // NOTES: // - Signing and saving is an atomic operation, the two cannot be separated. // - The stream passed to the Sign() method must be readable. doc.Sign(sp, stream); // Rewind the stream to read the document just created // into another GcPdfDocument and verify the signature: stream.Seek(0, SeekOrigin.Begin); var doc2 = new GcPdfDocument(); doc2.Load(stream); SignatureField sf2 = (SignatureField)doc2.AcroForm.Fields[0]; if (!sf2.Value.VerifySignatureValue()) throw new Exception("Failed to verify the signature"); // Done (the generated and signed document has already been saved to 'stream'). return doc.Pages.Count; } } }