''' <summary>
''' Adds the embedded PDF document to the specified PDF document and creates bookmark with link to the embedded PDF document.
''' </summary>
''' <param name="sourceDocumentFilename">The filename of source PDF document.</param>
''' <param name="embeddingDocumentFilename">The filename of PDF document that should be embedded.</param>
Public Shared Sub AddEmbeddedDocument(sourceDocumentFilename As String, embeddingDocumentFilename As String)
    ' open PDF document
    Using document As New Vintasoft.Imaging.Pdf.PdfDocument(sourceDocumentFilename)
        ' if document does not have embedded files
        If document.EmbeddedFiles Is Nothing Then
            ' create EmbeddedFiles dictionary
            document.EmbeddedFiles = New Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedFileSpecificationDictionary(document)
        End If

        ' name of embedded document
        Dim embeddedDocumentName As String = System.IO.Path.GetFileName(embeddingDocumentFilename)

        ' create embedded file, use ZIP compression
        Dim embeddedFile As New Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedFile(document, embeddingDocumentFilename, Vintasoft.Imaging.Pdf.PdfCompression.Zip)

        ' add embedded file to EmbeddedFiles
        document.EmbeddedFiles.Add(embeddedDocumentName, New Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedFileSpecification(System.IO.Path.GetFileName(embeddingDocumentFilename), embeddedFile))

        ' if document does not have bookmarks
        If document.Bookmarks Is Nothing Then
            ' create document bookmarks
            document.Bookmarks = New Vintasoft.Imaging.Pdf.Tree.PdfBookmarkCollection(document)
        End If

        ' create destination to the first page of document
        Dim destination As Vintasoft.Imaging.Pdf.Tree.PdfDestinationBase = New Vintasoft.Imaging.Pdf.Tree.PdfDestinationFit(document, 0)
        ' create target that goes to the embedded PDF document
        Dim actionTarget As New Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedGotoActionTarget(document, embeddedDocumentName)
        ' create embedded action that opens the first page in embedded PDF document
        Dim action As New Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedGotoAction(destination, actionTarget)

        ' create bookmark
        Dim bookmark As New Vintasoft.Imaging.Pdf.Tree.PdfBookmark(document)
        ' set the bookmark title
        bookmark.Title = embeddedDocumentName
        ' set the bookmark action
        bookmark.Action = action
        ' add bookmark to the document bookmarks
        document.Bookmarks.Add(bookmark)

        ' save changes in PDF document
        document.SaveChanges()
    End Using
End Sub

/// <summary>
/// Adds the embedded PDF document to the specified PDF document and creates bookmark with link to the embedded PDF document.
/// </summary>
/// <param name="sourceDocumentFilename">The filename of source PDF document.</param>
/// <param name="embeddingDocumentFilename">The filename of PDF document that should be embedded.</param>
public static void AddEmbeddedDocument(string sourceDocumentFilename, string embeddingDocumentFilename)
{
    // open PDF document
    using (Vintasoft.Imaging.Pdf.PdfDocument document = new Vintasoft.Imaging.Pdf.PdfDocument(sourceDocumentFilename))
    {
        // if document does not have embedded files
        if (document.EmbeddedFiles == null)
            // create EmbeddedFiles dictionary
            document.EmbeddedFiles = new Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedFileSpecificationDictionary(document);

        // name of embedded document
        string embeddedDocumentName = System.IO.Path.GetFileName(embeddingDocumentFilename);

        // create embedded file, use ZIP compression
        Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedFile embeddedFile =
            new Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedFile(document, embeddingDocumentFilename, Vintasoft.Imaging.Pdf.PdfCompression.Zip);

        // add embedded file to EmbeddedFiles
        document.EmbeddedFiles.Add(
            embeddedDocumentName,
            new Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedFileSpecification(System.IO.Path.GetFileName(embeddingDocumentFilename), embeddedFile));

        // if document does not have bookmarks
        if (document.Bookmarks == null)
            // create document bookmarks
            document.Bookmarks = new Vintasoft.Imaging.Pdf.Tree.PdfBookmarkCollection(document);

        // create destination to the first page of document
        Vintasoft.Imaging.Pdf.Tree.PdfDestinationBase destination =
            new Vintasoft.Imaging.Pdf.Tree.PdfDestinationFit(document, 0);
        // create target that goes to the embedded PDF document
        Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedGotoActionTarget actionTarget =
            new Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedGotoActionTarget(document, embeddedDocumentName);
        // create embedded action that opens the first page in embedded PDF document
        Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedGotoAction action =
            new Vintasoft.Imaging.Pdf.Tree.PdfEmbeddedGotoAction(destination, actionTarget);

        // create bookmark
        Vintasoft.Imaging.Pdf.Tree.PdfBookmark bookmark = new Vintasoft.Imaging.Pdf.Tree.PdfBookmark(document);
        // set the bookmark title
        bookmark.Title = embeddedDocumentName;
        // set the bookmark action
        bookmark.Action = action;
        // add bookmark to the document bookmarks
        document.Bookmarks.Add(bookmark);

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