How to generate QR Code and sign document using C# Leave feedback

The generated QR Code can be downloaded and used to add to the business contracts and official documents. Any QR Code contains unique textual information that confirms the identity of the signer or authorizes the business document. QR Code verification could be performed automatically by reading the contents of the QR Code embedded data. These signatures could be scanned automatically. The QR Code allows keeping over 2 Kilobytes of data.

GroupDocs.Signature for .NET provides API for signing a wide range of document formats. Moreover, API includes special abilities for additional document content processing. Supported formats are PDF, Microsoft Word, Microsoft PowerPoint, Microsoft Excel, PNG, JPEG, and many others.

Use the downloads section to obtain API DLLs or MSI installer or use the NuGet package manager:

PM> Install-Package GroupDocs.Signature

Sometimes it is needed to inform coworkers about business events. In such cases, an Event QR code can provide all the required information in a very effective way. This topic describes how to sign a PDF document with the generated Event QR code.

• Instantiate the Signature class providing the path to the source document or document stream.
• Set event data in the Event object instance.
• Create the QrCodeSignOptions object and set up all demanded fields.
• Invoke the Sign method to process the document, providing output file path and sign options.

            // instantiating the signature object
            using (Signature signature = new Signature(@"source.pdf"))
            {
                //provide event data
                Event eventQr = new Event()
                {
                    Title = "Meeting",
                    Description = "Productivity issues",
                    Location = "room 408",
                    StartDate = new DateTime(2022, 06, 19, 15, 30, 0),
                    EndDate = new DateTime(2022, 06, 19, 17, 0, 0)
                };

                // setup qrcode signature options
                QrCodeSignOptions signOptions = new QrCodeSignOptions()
                {
                    HorizontalAlignment = HorizontalAlignment.Right,
                    VerticalAlignment = VerticalAlignment.Bottom,
                    EncodeType = QrCodeTypes.QR,
                    Text = "",
                    Data = eventQr
                };

                // sign document
                signature.Sign(@"signed_event.pdf", signOptions);
            }

The result of signing a document may look like the picture below. Such QR codes can be very useful for organizing events.

To try signing documents with QR codes for free, you may use the QR Code Generator Online App.

Another way to improve documents is to generate the QR code first and then add it to documents using third-party tools. For this case, it is possible to generate code as an image.

• Create the QrCodeSignOptions instance and set up all demanded fields.
• Instantiate the PreviewSignatureOptions object providing the methods for creation and releasing.
• Invoke the GenerateSignaturePreview method to obtain the QR code image as a stream.
• Use the resultant QR Code stream in any possible way.

            MemoryStream result = new MemoryStream();
            // setup QR Code signature options
            QrCodeSignOptions signOptions = new QrCodeSignOptions()
            {
                EncodeType = QRCodeTypes.Code93Extended,
                Text = "Case 148.01"
            };

            //Instantiate preview options
            var previewOptions = new PreviewSignatureOptions(
                signOptions,
                delegate (PreviewSignatureOptions options) { return result; },
                delegate (PreviewSignatureOptions options, Stream signatureStream) { }
                );

            //Generate image to stream
            GroupDocs.Signature.Signature.GenerateSignaturePreview(previewOptions);

An image with the generated QR Code may look as below:

To use the API without evaluation limitations, you can get a free temporary license.

To sum up, some useful ways of processing documents with QR codes were discussed in this article. Using C# with .NET applications greatly improves the productivity of such actions. In addition, you can use the QR Code Generator Online App to generate QR codes and/or sign your files with QR codes for free.

Read the documentation to learn how to use GroupDocs.Signature in your .NET applications. Also, you may discuss any questions or issues at the GroupDocs forum.

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