How to add watermark to PDF using iText [duplicate] - itext

Question

I have been trying to add an image to all pages using itextsharp. The image needs to be OVER all content of every page. I have used the following code below all the otherdoc.add()
Document doc = new Document(iTextSharp.text.PageSize.A4, 10, 10, 30, 1);
PdfWriter writer = PdfWriter.GetInstance(doc, new FileStream(Server.MapPath("~/pdf/" + fname), FileMode.Create));
doc.Open();
Image image = Image.GetInstance(Server.MapPath("~/images/draft.png"));
image.SetAbsolutePosition(12, 300);
writer.DirectContent.AddImage(image, false);
doc.Close();
The above code only inserts an image in the last page. Is there any way to insert the image in the same way in all pages?

Answer 1

It's normal that the image is only added once; after all: you're adding it only once. (Or you've left away some essential steps in your code snippet: see the edit I made.)
In any case: you can solve your problem by using a page event. There are some examples in Java here: http://itextpdf.com/sandbox/events
Or you can consult chapter 5 of my book. All examples are available in Java as well as in C#.
You should create a document in 5 steps and add an event in step 2:
// step 1
Document document = new Document();
// step 2
PdfWriter writer = PdfWriter.GetInstance(document, stream);
MyEvent event = new MyEvent();
writer.PageEvent = event;
// step 3
document.Open();
// step 4
// Add whatever content you want to add
// step 5
document.Close();
You have to write the MyEvent class yourself:
protected class MyEvent : PdfPageEventHelper {
Image image;
public override void OnOpenDocument(PdfWriter writer, Document document) {
image = Image.GetInstance(Server.MapPath("~/images/draft.png"));
image.SetAbsolutePosition(12, 300);
}
public override void OnEndPage(PdfWriter writer, Document document) {
writer.DirectContent.AddImage(image);
}
}
The OnEndPage() in class MyEvent will be triggered every time the PdfWriter has finished a page. Hence the image will be added on every page.
Caveat: it is important to create the image object outside the OnEndPage() method, otherwise the image bytes risk being added as many times as there are pages in your PDF (leading to a bloated PDF).

Answer 2

Document document = new Document();
// step 2
PdfWriter writer = PdfWriter.GetInstance(document, stream);
final MyEvent event = new MyEvent();
writer.setPageEvent(event);
document.Open();
// Add whatever content you want to add
document.Close();
//Now Create The new class and override the onEndPage()
//I have used this for footer image but you can add wherever you want
//in the whole page using setAbsolutePosition(see below the class)
//I am using palyFramework with java
package controllers;
import java.io.IOException;
import java.nio.file.Files;
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Element;
import com.itextpdf.text.Font;
import com.itextpdf.text.Image;
import com.itextpdf.text.Phrase;
import com.itextpdf.text.pdf.ColumnText;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfPageEventHelper;
import com.itextpdf.text.pdf.PdfWriter;
import play.Play;
public class MyEvent extends PdfPageEventHelper{
#Override
public void onEndPage(final PdfWriter writer, final Document document)
{
final Font ffont = new Font(Font.FontFamily.TIMES_ROMAN,8,
Font.ITALIC);
Image img;
try {
final Phrase footer = new Phrase("Powered By :", ffont);
img=Image.getInstance(Files.readAllBytes(Play.application().getFile("/
img- path/Image.png").toPath()));
img.scaleToFit(60f, 40f);
img.setAbsolutePosition(510,5);
final PdfContentByte cb = writer.getDirectContent();
cb.addImage(img);
ColumnText.showTextAligned(cb, Element.ALIGN_CENTER,
footer,490, 15, 0);
} catch (IOException | DocumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}}
It works fine for me; refer to this link.