C#给PDF文件添加水印

本文实例为大家分享了C#添加PDF文件水印的具体代码，供大家参考，具体内容如下

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using iTextSharp.text.html.simpleparser;
using iTextSharp.text.pdf;
using iTextSharp.text;
using System.IO;
using System.Web.UI.HtmlControls;
using System.Drawing;

//itextsharp.dll version:5.1.10

protected void Button1_Click(object sender, EventArgs e)
 {
 string source =@"D:\My.Sample\C#NET\Exoport2PDF\Web2\Chap1011.pdf"; //模板路径
 string output = @"D:\My.Sample\C#NET\Exoport2PDF\Web2\Chap1012.pdf"; //导出水印背景后的PDF
 string watermark = @"D:\My.Sample\C#NET\Exoport2PDF\Web2\gp0.jpg"; // 水印图片

bool isSurrcess = PDFWatermark(source, output, watermark, 10, 10);

}

public bool PDFWatermark(string inputfilepath, string outputfilepath, string ModelPicName, float top, float left)

{
 //throw new NotImplementedException();
 PdfReader pdfReader = null;
 PdfStamper pdfStamper = null;
 try
 {
  pdfReader = new PdfReader(inputfilepath);

int numberOfPages = pdfReader.NumberOfPages;

iTextSharp.text.Rectangle psize = pdfReader.GetPageSize(1);

float width = psize.Width;

float height = psize.Height;

pdfStamper = new PdfStamper(pdfReader, new FileStream(outputfilepath, FileMode.Create));

PdfContentByte waterMarkContent;

iTextSharp.text.Image image = iTextSharp.text.Image.GetInstance(ModelPicName);

image.GrayFill = 20;//透明度，灰色填充
  //image.Rotation//旋转
  //image.RotationDegrees//旋转角度
  //水印的位置
  if (left < 0)
  {
   left = width - image.Width + left;
  }

image.SetAbsolutePosition(left, (height - image.Height) - top);

//每一页加水印,也可以设置某一页加水印
  for (int i = 1; i <= numberOfPages; i++)
  {
   waterMarkContent = pdfStamper.GetUnderContent(i);

waterMarkContent.AddImage(image);
  }
  //strMsg = "success";
  return true;
 }
 catch (Exception ex)
 {
   ex.Message.Trim();
  return false;
 }
 finally
 {

if (pdfStamper != null)
   pdfStamper.Close();

if (pdfReader != null)
   pdfReader.Close();
 }