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();
    }

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。