Adding Image watermark to Pdf while Creating it using iTextSharp

Question

Wonder if this possible. Saw many posts on adding watermark after the pdf is created and saved in disk. But during creation of document how do i add a image watermark. I kno

Answer 1

This is the accepted answer's port to C#, and what worked for me. I'm using an A4 page size:

Define this BackgroundImagePdfPageEvent class:

public class BackgroundImagePdfPageEvent : PdfPageEventHelper
{
    private readonly Image watermark;

    public BackgroundImagePdfPageEvent(string imagePath)
    {
        using (var fs = new FileStream(imagePath, FileMode.Open))
        {
            watermark = Image.GetInstance(System.Drawing.Image.FromStream(fs), ImageFormat.Jpeg);
            watermark.SetAbsolutePosition(0, 0);
            watermark.ScaleAbsolute(PageSize.A4.Width, PageSize.A4.Height);
            watermark.Alignment = Image.UNDERLYING;
        }
    }

    public override void OnStartPage(PdfWriter writer, Document document)
    {
        document.Add(watermark);
    }
}

Then, when creating your document:

var doc = new Document(PageSize.A4);
doc.SetMargins(60f, 60f, 120f, 60f);
var outputStream = new MemoryStream();
var writer = PdfWriter.GetInstance(doc, outputStream);
var imagePath = "PATH_TO_YOUR_IMAGE";
writer.PageEvent = new BackgroundImagePdfPageEvent(imagePath);