C#给PDF文件添加水印

这篇文章主要为大家详细介绍了C#给PDF文件添加水印的相关代码，文中示例代码介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴们可以参考一下

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

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									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();

									  }