Bagaimana untuk Menggabungkan Berbilang PDF Dijana Masa Jalan Menggunakan ITextSharp?

byte[] mergedPdf = null;
using (MemoryStream ms = new MemoryStream())
{
    using (Document document = new Document())
    {
        using (PdfCopy copy = new PdfCopy(document, ms))
        {
            document.Open();

            for (int i = 0; i < pdfBytes.Count; ++i)
            {
                PdfReader reader = new PdfReader(pdfBytes[i]);

                int n = reader.NumberOfPages;
                for (int page = 0; page < n; )
                {
                    copy.AddPage(copy.GetImportedPage(reader, ++page));
                }
            }
        }
    }
    mergedPdf = ms.ToArray();
}

using (MemoryStream ms = new MemoryStream())
{
    using (Document document = new Document())
    {
        using (PdfWriter writer = PdfWriter.GetInstance(document, ms))
        {
            document.Open();

            for (int i = 0; i < pdfBytes.Count; ++i)
            {
                PdfReader reader = new PdfReader(pdfBytes[i]);

                int n = reader.NumberOfPages;
                for (int page = 0; page < n; )
                {
                    PdfImportedPage importedPage = writer.GetImportedPage(reader, ++page);
                    writer.Add(importedPage);
                }

                reader.Close();
            }
        }
    }
    mergedPdf = ms.ToArray();
}