IPdfSignatureOptionsProviderAsync Interface

When implemented, provides asynchronous access to digital signatures in the Web Document Viewer.

Namespace: DevExpress.XtraReports.Web.WebDocumentViewer

Assembly: DevExpress.XtraReports.v26.1.dll

Declaration

C#

public interface IPdfSignatureOptionsProviderAsync

VB.NET

Public Interface IPdfSignatureOptionsProviderAsync

Remarks

In MVC and Web Forms applications, use a synchronous approach to get a dictionary of available signatures. If you use asynchronous code to get the signatures, pass false to the ConfigureAwait method throughout the entire chain of methods:

C#

public async Task<Dictionary<string, PdfSignatureOptions>> GetAvailableOptionsAsync() {
    var signatures = await GetMySignaturesAsync(...).ConfigureAwait(false);
    return signatures;
}

VB

Public Async Function GetAvailableOptionsAsync() As Task(Of Dictionary(Of String, PdfSignatureOptions))
  Dim signatures = Await GetMySignaturesAsync(...).ConfigureAwait(False)
  Return signatures
End Function

Example

The following example shows how to sign a document exported to PDF from the Web Document Viewer’s UI:

View Example: How to Sign the Exported PDF Document

Implement the IPdfSignatureOptionsProviderAsync interface to register signatures. The GetAvailableOptionsAsync() method returns a dictionary of value pairs: signature certificate identifiers and PdfSignatureOptions objects:

using System;
using System.Collections.Generic;
using System.IO;
using System.Threading.Tasks;
using DevExpress.XtraPrinting;
using DevExpress.XtraReports.Web.WebDocumentViewer;
using Microsoft.AspNetCore.Hosting;

namespace SignPdfDocumentExample.Services {
    public class CustomPdfSignatureOptionsProviderAsync : IPdfSignatureOptionsProviderAsync {
        readonly Dictionary<string, PdfSignatureOptions> signatures = new Dictionary<string, PdfSignatureOptions>();
        public CustomPdfSignatureOptionsProviderAsync(IWebHostEnvironment webHostEnvironment) {
            var signatureDictionaryPath = Path.Join(webHostEnvironment.ContentRootPath, "Signatures");
            signatures.Add(Guid.NewGuid().ToString(), new PdfSignatureOptions() {
                Certificate = new System.Security.Cryptography.X509Certificates.X509Certificate2(Path.Combine(signatureDictionaryPath, "certificate.pfx"), "123"),
                ContactInfo = "Jane Cooper",
            });
            signatures.Add(Guid.NewGuid().ToString(), new PdfSignatureOptions() {
                Certificate = new System.Security.Cryptography.X509Certificates.X509Certificate2(Path.Combine(signatureDictionaryPath, "certificate.pfx"), "123"),
                ContactInfo = "John Smith",
                Location = "Australia",
                Reason = "I Agree",
                ImageSource = DevExpress.XtraPrinting.Drawing.ImageSource.FromFile(Path.Combine(signatureDictionaryPath, "John_Smith.png"))
            });
        }

        public Task<Dictionary<string, PdfSignatureOptions>> GetAvailableOptionsAsync() {
            return Task.FromResult(signatures);
        }
    }
}

To sign a report, select a signature from the drop-down list in PDF Export Options:

You can also specify or modify ContactInfo, Location, Reason, and AccessibleDescription in the Signature Options section. These fields are populated with signature attributes specified in the IPdfSignatureOptionsProviderAsync implementation. Changes affect only the exported PDF document.

During export to PDF, XRPdfSignature is converted to a signature with the specified settings: