Code samples

ZUGFeRD document is PDF/A-3b document with embedded ZUGFeRD invoice.

For getting ZUGFeRD document it is necessary to do the following steps:

• Create the ZUGFeRD invoice in XML format. This step can be made using the ZUGFeRD library: https://github.com/ZUGFeRD/ZUGFeRD-csharp
• Open the PDF document. This step can be made using VintaSoft Imaging .NET SDK.
• Embed the ZUGFeRD invoice into PDF document. This step can be made using VintaSoft Imaging .NET SDK.
• Convert the PDF document to a PDF/A-3b document. This step can be made using VintaSoft Imaging .NET SDK.
• Make the PDF/A-3b document compatible with ZUGFeRD standard by updating metadata of PDF/A-3b document. This step can be made using VintaSoft Imaging .NET SDK.

Here is C# code snippet that shows how to create ZUGFeRD PDF document using VintaSoft Imaging .NET SDK:

using System;

namespace CreateZugferd2_0_PdfDocument
{
    class Program {

        static void Main(string[] args) {
            CreateZugferd2_0_PdfDocument("blank.pdf", "zugferd-invoice.xml", "zugferd2_0_pdfFile.pdf");
        }

        /// <summary>
        /// Creates the ZUGFeRD 2.0 PDF document.
        /// </summary>
        /// <param name="sourcePdfFilePath">Path to a source PDF document.</param>
        /// <param name="zugferdIvoiceFilePath">Path to a ZUGFeRD invoice.</param>
        /// <param name="destPdfFilePath">Path to a ZUGFeRD PDF document.</param>
        static void CreateZugferd2_0_PdfDocument(
            string sourcePdfFilePath,
            string zugferdIvoiceFilePath,
            string destPdfFilePath)
        {
            // copy source PDF document to a destination PDF document
            System.IO.File.Copy(sourcePdfFilePath, destPdfFilePath, true);

            // embed the ZUGFeRD invoice into PDF document
            EmbedZugferdIvoiceIntoPdfDocument(destPdfFilePath, zugferdIvoiceFilePath);

            // convert PDF document to PDF/A-3b document
            if (!ConvertPdfDocumentToPdfA3bDocument(destPdfFilePath))
                return;

            // update metadata in PDF document
            UpdatePdfDocumentMetadata(destPdfFilePath, zugferdIvoiceFilePath);
        }

        /// <summary>
        /// Embeds a ZUGFeRD invoice to a PDF document.
        /// </summary>
        static void EmbedZugferdIvoiceIntoPdfDocument(
            string zugferdPdfFilePath,
            string zugferdIvoiceFilePath)
        {
            // get name of file with ZUGFeRD invoice
            string zugferdIvoiceFileName = System.IO.Path.GetFileName(zugferdIvoiceFilePath);

            // open destination PDF document
            using (Vintasoft.Imaging.Pdf.PdfDocument pdfDoc = new Vintasoft.Imaging.Pdf.PdfDocument(zugferdPdfFilePath))
            {
                // if PDF document does NOT have embedded files
                if (pdfDoc.EmbeddedFiles == null)
                {
                    // creates a dictionary for embedded files
                    pdfDoc.EmbeddedFiles = new Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedFileSpecificationDictionary(pdfDoc);
                }

                // create a PDF embedded file, which contains ZUGFeRD invoice
                Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedFile embeddedFile = new Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedFile(pdfDoc, zugferdIvoiceFilePath);
                // specify the subtype of PDF embedded file
                embeddedFile.Subtype = "text/xml";
                // specify the modification date of PDF embedded file
                embeddedFile.ModifyDate = DateTime.Now;

                // create the file specification for embedded file
                Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedFileSpecification embeddedFileSpecification = new Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedFileSpecification(zugferdIvoiceFileName, embeddedFile);
                // describe the embedded file
                embeddedFileSpecification.Description = zugferdIvoiceFileName;

                // get the file specification dictionary
                Vintasoft.Imaging.Pdf.BasicTypes.PdfDictionary fileSpecificationDictionary = embeddedFileSpecification.BasicObject as Vintasoft.Imaging.Pdf.BasicTypes.PdfDictionary;
                // add a Unicode text string that provides file specification to the file specification dictionary
                fileSpecificationDictionary.Add("UF", new Vintasoft.Imaging.Pdf.BasicTypes.PdfString(zugferdIvoiceFileName));

                // add the embedded file to the PDF document
                pdfDoc.EmbeddedFiles.Add(zugferdIvoiceFileName, embeddedFileSpecification);

                // get a dictionary containing a subset of the keys F, UF, DOS, Mac, and Unix from the file specification dictionary
                Vintasoft.Imaging.Pdf.BasicTypes.PdfDictionary efDictionary = fileSpecificationDictionary["EF"] as Vintasoft.Imaging.Pdf.BasicTypes.PdfDictionary;
                // add information about embedded file into the EF dictionary
                efDictionary.Add("UF", embeddedFile.IndirectReference);

                // save changes in PDF document
                pdfDoc.SaveChanges();
            }
        }

        /// <summary>
        /// Converts a PDF document to a PDF/A-3b document.
        /// </summary>
        static bool ConvertPdfDocumentToPdfA3bDocument(string filePath)
        {
            try
            {
                // create PDF/A-3b converter
                Vintasoft.Imaging.Pdf.Processing.PdfA.PdfAConverter converter = new Vintasoft.Imaging.Pdf.Processing.PdfA.PdfA3bConverter();
                converter.LzwFixupCompression = Vintasoft.Imaging.Pdf.PdfCompression.Zip;

                Vintasoft.Imaging.Processing.ProcessingState processingState = new Vintasoft.Imaging.Processing.ProcessingState();
                processingState.Progress += ProcessingState_Progress;

                // create temporary PDF file
                string tempPdfFile = System.IO.Path.GetTempFileName();

                // convert source PDF document and save to the temporary PDF file
                Vintasoft.Imaging.Processing.ConversionProfileResult conversionProfileResult = converter.Convert(filePath, tempPdfFile, processingState);

                // if PDF document is successfully converted to a PDF/A-3b
                if (conversionProfileResult.IsSuccessful)
                {
                    // copy the temporary PDF file over the source PDF file
                    System.IO.File.Copy(tempPdfFile, filePath, true);
                    return true;
                }
                else
                {
                    // for each conversion error
                    foreach (Vintasoft.Imaging.Processing.IProcessingCommandInfo cmd in conversionProfileResult.ActivatedTriggers.Keys)
                    {
                        // output information about error
                        Console.WriteLine(string.Format("Error: {0} ({1} matches)", cmd, conversionProfileResult.ActivatedTriggers[cmd].Count));
                    }
                    return false;
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(string.Format("Error: {0}", ex.Message));
                return false;
            }
        }

        private static void ProcessingState_Progress(object sender, Vintasoft.Imaging.ProgressEventArgs e)
        {
        }

        /// <summary>
        /// Updates metadata in PDF document.
        /// </summary>
        static void UpdatePdfDocumentMetadata(string pdfFilePath, string zugferdIvoiceFilePath)
        {
            // open PDF document
            using (Vintasoft.Imaging.Pdf.PdfDocument pdfDoc = new Vintasoft.Imaging.Pdf.PdfDocument(pdfFilePath))
            {
                // get name of file with ZUGFeRD invoice
                string zugferdIvoiceFileName = System.IO.Path.GetFileName(zugferdIvoiceFilePath);

                // get PDF document metadata
                string origMeta = System.Text.Encoding.UTF8.GetString(pdfDoc.Metadata);

                // update metadata
                origMeta = origMeta.Replace("xmlns:dc=", " " + Properties.Resources.xmlPart1 + " " + Properties.Resources.xmlPart3 + " xmlns:dc=");
                origMeta = origMeta.Replace("</dc:creator>", " </dc:creator> " + Properties.Resources.xmlPart2);
                origMeta = origMeta.Replace("%filename%", zugferdIvoiceFileName);

                // save metadata back to PDF document
                pdfDoc.Metadata = System.Text.Encoding.UTF8.GetBytes(origMeta);

                // save changes in PDF document
                pdfDoc.SaveChanges();
            }
        }

    }
}

Source codes of console application, which uses VintaSoft Imaging .NET SDK 14.0 and creates ZUGFeRD 1.0 PDF document, can be downloaded from here.

Source codes of console application, which uses VintaSoft Imaging .NET SDK 14.0 and creates ZUGFeRD 2.0 PDF document, can be downloaded from here.


Created ZUGFeRD PDF document can be validated using free validators:

• https://www.zugferd-community.net/de/op ... validation
• https://www.din-zugferd-validation.org