我的代码如下：

var doc = new Document();
        PdfWriter.GetInstance(doc,new FileStream(Server.MapPath("~/QrCodes/") + fileName + ".pdf",FileMode.Create));
        doc.Open();
        PdfPTable table = new PdfPTable(2);
        table.WidthPercentage = 100;
 
        foreach (var item in items)
        {
            if (itemImages.Any(p => p.Reference == item.Reference) == true)
            {
                System.Drawing.Image image = System.Drawing.Image.FromFile(Server.MapPath(@item.ItemQrCode));
                iTextSharp.text.Image pdfImage = iTextSharp.text.Image.GetInstance(image,ImageFormat.Jpeg);
 
                PdfPCell cellImage = new PdfPCell(pdfImage);
                cellImage.HorizontalAlignment = Element.ALIGN_CENTER;
                cellImage.VerticalAlignment = Element.ALIGN_MIDDLE;
                cellImage.Border = 0;
 
                table.AddCell(cellImage);
 
            }
 
        }
 
        doc.Add(table);
        doc.Close();