PDF打水印加密

 using System;
 using System.Collections.Generic;
 using System.Data;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Web;
 using iTextSharp.text;
 using iTextSharp.text.pdf;
 using iTextSharp.text.html;
 using iTextSharp.text.xml;
 using System.Configuration;

 namespace WorkFlow
 {
     public class ReportHelper
     {
         public static string  ConvertToPDF(string content)
         {
             string s = string.Empty;
             string sPwd = string.Empty;
             StringReader sr = new StringReader(content);
             //定义一个Document，并设置页面大小为A4，竖向
             Document document = new Document(PageSize.A4);
             string sMapPath = HttpContext.Current.Server.MapPath(GetWebMailKeyValue()) + @"\";
             string sFileName = "Report" + DateTime.Now.ToString("yyyyMMddHHmmss") + ".pdf";

             try
             {
                 DirectoryInfo info = new DirectoryInfo(sMapPath);
                 if (!info.Exists)
                 {
                     info.Create();
                 }
                 PdfWriter writer = PdfWriter.GetInstance(document, new FileStream(sMapPath + sFileName, FileMode.Create));
                 #region 载入亚洲字体资源，无此操作的话，不能显示包括中文、日文、韩文等内容
                 BaseFont.AddToResourceSearch("iTextAsian.dll");
                 BaseFont.AddToResourceSearch("iTextAsianCmaps.dll");
                 BaseFont bf = BaseFont.CreateFont("C:/WINDOWS/Fonts/SIMYOU.TTF", BaseFont.IDENTITY_H, BaseFont.NOT_EMBEDDED);
                 #endregion

                 //生成水印
                 writer.PageEvent = new PdfEventHanler("@JTSJMZT", bf);

                 //处理密码
                 if (string.IsNullOrEmpty(sPwd))
                 {
                     Random r = new Random();
                     sPwd = r.Next(, ).ToString();
                 }
                 //将密码存入数据库
                 //sPwd

                 //加密
                 writer.SetEncryption(PdfWriter.STRENGTH128BITS, sPwd, null, PdfWriter.AllowPrinting);

                 //打开document
                 document.Open();

                 //写入一个段落, Paragraph
                 //List<IElement> htmlarraylist = iTextSharp.text.html.simpleparser.HTMLWorker.ParseToList(sr, null).ToArray().ToList<IElement>();

                 //for (int k = 0; k < htmlarraylist.Count; k++)
                 //    document.Add(htmlarraylist[k]);

                 //Paragraph mypara = new Paragraph();
                 //document.Add(mypara);

                 document.Add(new Paragraph(content, new Font(bf, )));

                 //关闭document
                 document.Close();

                 s = sFileName;
                 //打开PDF，看效果
                 //Process.Start(s);

                 //Blob Storage
                 //var location = AppDomain.CurrentDomain.BaseDirectory;
                 //uploadPath = location + "/";
                 //doc.Save(uploadPath + sFileName);
                 //BlobClient.AddBlob(DANCode1Config.EmailFileContainer, "MailExportAttachment1/" + sFileName, uploadPath, sFileName);

                 //uploadPath = GetWebMailURL() + "MailExportAttachment1/" + sFileName;

                 //s = "{\"message\":true,\"value\":\"" + s + "\"}";
             }
             catch (Exception ex)
             {
                 s= ex.Message;
             }
             return s;
         }

         public static string GetWebMailURL()
         {
             string s = ConfigurationManager.AppSettings["MailBlobStorage"].ToString();
             return s;
         }

         public static string GetWebMailKeyValue()
         {
             string s = ConfigurationManager.AppSettings["PDFExport"].ToString();
             return s;
         }
     }

     internal class PdfEventHanler : PdfPageEventHelper
     {
         string m_WatermaskText;
         BaseFont m_WatermaskTextFont;

         /// <summary>
         ///
         /// </summary>
         /// <param name="watermaskText">水印文字的内容</param>
         /// <param name="watermaskTextFont">水印文字的字体</param>
         public PdfEventHanler(string watermaskText,
      BaseFont watermaskTextFont)
         {
             m_WatermaskText = watermaskText;
             m_WatermaskTextFont = watermaskTextFont;
         }

         /// <summary>
         /// 在Page End事件中，添加页面水印，此事件在每页均会发生
         /// </summary>
         /// <param name="writer"></param>
         /// <param name="document"></param>
         public override void OnEndPage(PdfWriter writer,
     Document document)
         {
             PdfGState gstate = new PdfGState();
             gstate.FillOpacity = 0.2f; //设置灰度和透明度
             gstate.StrokeOpacity = 0.2f;

             //水印内容，必须放置在底层
             PdfContentByte wm = writer.DirectContentUnder;
             wm.SaveState();
             wm.SetGState(gstate);

             #region 给页面添加文字水印
             wm.SetFontAndSize(m_WatermaskTextFont, );
             wm.BeginText();
             wm.ShowTextAligned(Element.ALIGN_CENTER, m_WatermaskText,
     document.PageSize.Width / , document.PageSize.Height / , -35f);
             wm.EndText();
             #endregion

             wm.RestoreState();

             base.OnEndPage(writer, document);
         }
     }
 }