Converting Multiple Images into Multiple Pages PDF using itextsharp

问题

I have requirement to convert images into PDF with a template. I'm able to create one page PDF using itextsharp. Assumption 1 image for 1 page PDF. The problem comes when I have multiple images. How I can create multiple pages PDF with predefined template. Below is my code:

public static string CreatePDFDocument(string docname, string imagePath, string mediaField)
    {
        PdfReader pdfReader = null;
        string pdfPortrait = ConfigurationManager.AppSettings["PdfPortraitTemplate"];
        string pdfLandscape = ConfigurationManager.AppSettings["PdfLandscapeTemplate"];

        iTextSharp.text.Image instanceImg = iTextSharp.text.Image.GetInstance(imagePath);

        string filename = ConfigurationManager.AppSettings["LocalFolder"] + docname + ".pdf";

        FileStream pdfOutputFile = new FileStream(filename, FileMode.Create);

        if (instanceImg.ScaledHeight >= instanceImg.ScaledWidth)
        {
            pdfReader = new PdfReader(pdfPortrait);
        }
        else
        {
            pdfReader = new PdfReader(pdfLandscape);
        }

        PdfStamper pdfStamper = null;
        pdfStamper = new PdfStamper(pdfReader, pdfOutputFile);

        AcroFields testForm = pdfStamper.AcroFields;
        testForm.SetField("MediaField", mediaField);

        PdfContentByte overContent = pdfStamper.GetOverContent(1);
        IList<AcroFields.FieldPosition> fieldPositions = testForm.GetFieldPositions("ImageField");

        if (fieldPositions == null || fieldPositions.Count <= 0) throw new ApplicationException("Error locating field");
        AcroFields.FieldPosition fieldPosition = fieldPositions[0];
        iTextSharp.text.Rectangle imageRect = new Rectangle(fieldPosition.position.Top, fieldPosition.position.Left, fieldPosition.position.Bottom, fieldPosition.position.Right);

        instanceImg.ScaleToFit(imageRect.Height, -1 * imageRect.Width);
        instanceImg.SetAbsolutePosition(fieldPosition.position.Left, (fieldPosition.position.Top - (instanceImg.ScaledHeight)));

        overContent.AddImage(instanceImg);
        pdfStamper.FormFlattening = true;

        pdfStamper.Close();
        pdfReader.Close();

        return filename;
    }

Thanks in advance!

回答1:

Finally I found the solution,

Here is my final code

        public static string MainStamping(string docname, List<string> imagePath, string mediaField)
        {
            string filename = ConfigurationManager.AppSettings["LocalFolder"] + docname + ".pdf";

            FileStream pdfOutputFile = new FileStream(filename, FileMode.Create);
            PdfConcatenate pdfConcatenate = new PdfConcatenate(pdfOutputFile);

            PdfReader result = null;

            for (int i = 0; i < imagePath.Count; i++)
            {
                result = CreatePDFDocument1(imagePath[i], mediaField);
                pdfConcatenate.AddPages(result);
            }

            pdfConcatenate.Close();
            return filename;
        }

        public static PdfReader CreatePDFDocument1(string imagePath, string mediaField)
        {
            PdfReader pdfReader = null;
            string pdfPortrait = ConfigurationManager.AppSettings["PdfPortraitTemplate"];
            string pdfLandscape = ConfigurationManager.AppSettings["PdfLandscapeTemplate"];

            iTextSharp.text.Image instanceImg = iTextSharp.text.Image.GetInstance(imagePath);

            if ((instanceImg.ScaledHeight >= instanceImg.ScaledWidth) || (instanceImg.ScaledWidth <= 714 ))
            {
                pdfReader = new PdfReader(pdfPortrait);
            }
            else
            {
                pdfReader = new PdfReader(pdfLandscape);
            }

            MemoryStream memoryStream = new MemoryStream();
            PdfStamper pdfStamper = new PdfStamper(pdfReader, memoryStream);

            AcroFields testForm = pdfStamper.AcroFields;
            testForm.SetField("MediaField", mediaField);

            PdfContentByte overContent = pdfStamper.GetOverContent(1);
            IList<AcroFields.FieldPosition> fieldPositions = testForm.GetFieldPositions("ImageField");

            if (fieldPositions == null || fieldPositions.Count <= 0) throw new ApplicationException("Error locating field");
            AcroFields.FieldPosition fieldPosition = fieldPositions[0];
            iTextSharp.text.Rectangle imageRect = new Rectangle(fieldPosition.position.Top, fieldPosition.position.Left, fieldPosition.position.Bottom, fieldPosition.position.Right);

            instanceImg.ScaleToFit(imageRect.Height, -1 * imageRect.Width);
            instanceImg.SetAbsolutePosition(fieldPosition.position.Left, (fieldPosition.position.Top - (instanceImg.ScaledHeight)));

            overContent.AddImage(instanceImg);
            pdfStamper.FormFlattening = true;
            pdfStamper.Close();

            PdfReader resultReader = new PdfReader(memoryStream.ToArray());
            pdfReader.Close();

            return resultReader;
        }

Thanks,

来源：https://stackoverflow.com/questions/20485886/converting-multiple-images-into-multiple-pages-pdf-using-itextsharp