Embedded File Streams - Overview

As of 2024 Q1 RadPdfProcessing allows embedding file streams into the document. Thus, the content of the referenced files is embedded directly within the body of the PDF file.

The EmbeddedFile Class

RadFixedDocument stores the integrated files in an EmbeddedFilesCollection accessed by the EmbeddedFiles property. Each EmbeddedFile contains Name (string) and Data (byte[]) properties. The specified Name should be unique and it represents the textual description of the embedded file, which can be displayed in the user interface of a viewer application. The Data stores the byte[] of the file stream.

The Name for the EmbeddedFile should contain the file extension as well, e.g. MySampleTextFile.txt.

Creating an Embedded File Stream

Creating an embedded file stream

        RadFixedDocument document = new RadFixedDocument(); 
        RadFixedPage page = document.Pages.AddPage(); 
        byte[] textFile = File.ReadAllBytes(@"....\Embedded_File_Streams.txt"); 
        document.EmbeddedFiles.Add("Text file.txt", textFile); 
        byte[] imageFile = File.ReadAllBytes(@"....\Basel.JPG"); 
        document.EmbeddedFiles.Add("Basel photo.jpg", imageFile);

DuplicatedEmbeddedFileNameException is thrown when adding an embedded file with a name that is already added to the collection.

Attachments section in Adobe

Embedded Files in a PDF document

Creating an Embedded Electronic (ZUGFeRD) Invoice

RadPdfProcessing provides support for embedding of ZUGFeRD (acronym for Zentraler User Guide des Forums elektronische Rechnung Deutschland) invoices.

Add ZUGFeRD invoice

        RadFixedDocument document = new RadFixedDocument(); 
        using (RadFixedDocumentEditor editor = new RadFixedDocumentEditor(document)) 
        { 
            editor.CharacterProperties.TrySetFont(new System.Windows.Media.FontFamily("Calibri")); 
            editor.InsertRun("PDF/A-3B Compliant Invoice"); 
        }; 
        byte[] bytes = File.ReadAllBytes(@"zugferd-invoice.xml"); 
        document.EmbeddedFiles.AddZugferdInvoice(bytes); 
 
        PdfFormatProvider provider = new PdfFormatProvider(); 
        PdfExportSettings settings = new PdfExportSettings(); 
        settings.ComplianceLevel = PdfComplianceLevel.PdfA3B; 
        provider.ExportSettings = settings;  
        using (Stream output = File.OpenWrite("exportedInvoice.pdf")) 
        {  
            provider.Export(document, output); 
        }

Only a single XML invoice attachment is allowed according to ZUGFeRD standard.

To comply with the PDF/A-3B standard all the fonts in the documents should be embedded, so please avoid using Standard Fonts because they are not being embedded in the document.

Remove ZUGFeRD invoice

        if (document.EmbeddedFiles.ContainsZugferdInvoice) 
        { 
            document.EmbeddedFiles.RemoveZugferdInvoice(); 
        }

Using the MergedEmbeddedFileNameResolving event

The MergedEmbeddedFileNameResolving event occurs when trying to resolve conflicts between the embedded file names while merging RadFixedDocument instances. The DuplicatedEmbeddedFileNameResolvingEventArgs allows you to specify the NewName to be used for adding the file to the EmbeddedFiles collection.

DuplicatedEmbeddedFileNameResolvingEventArgs	Description
Name	Gets the current embedded file name.
NewName	Gets or sets the new embedded file name.
UsedNames	Gets the names that are already used for embedded files in the same RadFixedDocument.

Resolving Duplicated Names

        RadFixedDocument doc1 = new RadFixedDocument(); 
        RadFixedPage page1 = doc1.Pages.AddPage();           
        byte[] textFile1 = File.ReadAllBytes(@"....\Embedded_File_Streams.txt"); 
        doc1.EmbeddedFiles.Add("Text file.txt", textFile1);  
        byte[] imageFile = File.ReadAllBytes(@"....\Basel.JPG"); 
        doc1.EmbeddedFiles.Add("Basel photo.jpg", imageFile); 
 
        RadFixedDocument doc2 = new RadFixedDocument(); 
        RadFixedPage page2 = doc2.Pages.AddPage();            
        byte[] textFile2 = File.ReadAllBytes(@"....\Release_Notes.txt"); 
        doc2.EmbeddedFiles.Add("Text file.txt", textFile2); 
 
        doc1.MergedEmbeddedFileNameResolving += (s, a) => 
        { 
            string myNewName = "2_" + a.Name; 
            if (!a.UsedNames.Contains(myNewName)) 
            { 
                a.NewName = myNewName; 
            } 
        }; 
 
        doc1.Merge(doc2);

Resolved Duplicated Names

Resolving duplicated Names in Embedded Files

Using the PdfImportSettings.DuplicatedEmbeddedFileNameResolving event

When importing a PDF document containing embedded files, the DuplicatedEmbeddedFileNameResolving event that the PdfImportSettings offers, allows you to handle duplicated names and properly resolve them.