Setting cover sheet of PDF portfolio as first file using iText7 C#

Question

I would like to set the an attachment file at the cover sheet of my Pdf portfolio. In my code I have to add doc.Add(new Paragraph("Portable collection")); otherwise it will show "the document has no page" error. Any idea to have a file at cover sheet instead of having to add new page? Thanks.

My code:

    public Stream ExportPortfolio()
    {
        DateTime dateTime = DateTime.UtcNow.Date;
        CreatePortfolio port = new CreatePortfolio();
        //dummy files in local
        Dictionary<string, FileStream> dict = new Dictionary<string, FileStream>() {
            { "pdf.pdf", File.OpenRead("C:\\training\\pdf.pdf") },
            { "text.txt", File.OpenRead("C:\\training\\text.txt") },
        };
  
        WebOperationContext.Current.OutgoingResponse.ContentType = "application/octet-stream";
        WebOperationContext.Current.OutgoingResponse.Headers.Add("content-disposition", "inline; filename=" + $"{dateTime.ToString("dd/MM/yyyy")}_portfolio.pdf");
        return ManipulatePdf(dict);
    }

    public Stream ManipulatePdf(Dictionary<string, FileStream> Portfolios)
    {
        MemoryStream stream = new MemoryStream();
        PdfDocument pdfDoc = new PdfDocument(new PdfWriter(stream));
        Document doc = new Document(pdfDoc);
        
        doc.Add(new Paragraph("Portable collection"));

        PdfCollection collection = new PdfCollection();
        collection.SetView(PdfCollection.TILE);
        pdfDoc.GetCatalog().SetCollection(collection);

        foreach (var item in Portfolios)
        {
            AddFileAttachment(pdfDoc, item.Value, item.Key);
        }

        doc.Close();
        byte[] file = stream.ToArray();
        MemoryStream output = new MemoryStream();
        output.Write(file, 0, file.Length);
        output.Position = 0;

        return output;
    }

    private void AddFileAttachment(PdfDocument document, FileStream fileStream, string fileName)
    {
        string embeddedFileName = fileName;
        string embeddedFileDescription = fileName;
        string fileAttachmentKey = fileName;
        PdfFileSpec fileSpec = PdfFileSpec.CreateEmbeddedFileSpec(document, fileStream, embeddedFileDescription,
            embeddedFileName, null, null);
        document.AddFileAttachment(fileAttachmentKey, fileSpec);
    }

Answer 1

What you are missing is the usage of PDFCollection class. You can use it to set the initial document property for the cover page in the ManipulatePDF method/function in your code above.

PdfCollection collection = new PdfCollection();
collection.SetView(PdfCollection.TILE);
pdfDoc.GetCatalog().SetCollection(collection);
collection.SetInitialDocument("");

This should help with setting the first page of the PDF as cover page for PDF portfolio.