如何在中间底部添加水印

Question

I'm trying to add a watermark in a pdf file in the center bottom of pdf file .. I tried many ways but i did not figure out how it's works exactly to select the location of watermark.

Anyway here is the code:

string filepath = @"~/Images/logo-01.png";
                iTextSharp.text.Image pageIn = iTextSharp.text.Image.GetInstance(Server.MapPath(filepath));


                pageIn.Alignment = iTextSharp.text.Image.ALIGN_MIDDLE;
                pageIn.ScaleToFit(150, 150);
                pageIn.Alignment = iTextSharp.text.Image.UNDERLYING;
                pageIn.SetAbsolutePosition((PageSize.A4.Width - pageIn.ScaledWidth) / 2, (PageSize.A4.Height - pageIn.ScaledHeight) / 10);

Again i want to make the watermark position in the max center bottom of the page.

Answer 1

You may try using GroupDocs.Watermark for .NET that allows controlling the horizontal and vertical position of the watermark in the documents. This is how you can add watermark at the bottom of the pages in a PDF document:

using (PdfDocument doc = Document.Load<PdfDocument>("D:\\sample.pdf"))
{
        // Add text watermark
        TextWatermark watermark = new TextWatermark("Protected Document", new Font("Arial", 8));
        watermark.HorizontalAlignment = HorizontalAlignment.Center;
        watermark.VerticalAlignment = VerticalAlignment.Bottom;
        doc.AddWatermark(watermark);

        // Add image watermark
        ImageWatermark imageWatermark = new ImageWatermark("D:\\watermark.png");
        imageWatermark.HorizontalAlignment = HorizontalAlignment.Center;
        imageWatermark.VerticalAlignment = VerticalAlignment.Bottom;
        doc.AddWatermark(imageWatermark);

        // Save document
        doc.Save("D:\\output.pdf");
}

Disclosure: I work as a Developer Evangelist at GroupDocs.