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(0, 99999999).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, 12)));

                //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, 50);
            wm.BeginText();
            wm.ShowTextAligned(Element.ALIGN_CENTER, m_WatermaskText,
    document.PageSize.Width / 2, document.PageSize.Height / 2, -35f);
            wm.EndText();
            #endregion

            wm.RestoreState();

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