using System.IO;

using iTextSharp.text;

using iTextSharp.text.pdf;

//需要在项目里引用ICSharpCode.SharpZipLib.dll和itextsharp.dll

public string TxtFilePath;

public string SavePdfPath;//保存PDF的路径

  #region 读取TXT内容

        private string ReadXieyi(string FilePath)

        {

            string xieyi = "";

            FileInfo fi = new FileInfo(FilePath);

            StreamReader sr = fi.OpenText();

            xieyi = sr.ReadToEnd();

            sr.Close();

            return xieyi;

        }

        #endregion

        #region 创建PDF文档方法

        private void zscsc()

        {

            Document document = new Document(PageSize.A4);

            try

            {

                //<appSettings>

                // <add key="TxtFilePath" value="config/pubcode/"/>

                //<!-- 在WEBCOFIG里面加上的节点( value值是WebUI下的config/pubcode/)包文件保存在指定的文件下 -->

                //<appSettings>

                string name = Online.WebUI.AccountController.LoginName + "_" + _pic_id + ".pdf";

                SavePdfPath = AppDomain.CurrentDomain.BaseDirectory.ToString() + ConfigurationSettings.AppSettings["SavePdfPath"] + name;

               // object filename = "C://" + name; //filename,文件保存路径

           PdfWriter writer = PdfWriter.getInstance(document, new FileStream(SavePdfPath.ToString(), FileMode.Create));

                document.addTitle("图片授权协议");

                document.addAuthor("Quanjing.COM");

                document.addHeader("Expires", "0");

                document.Open();

                BaseFont bfSun = BaseFont.createFont(@"c:\windows\fonts\SIMKAI.TTF", BaseFont.IDENTITY_H, false); //调用的字体

                Font font = new Font(bfSun, 15);

                String text = "                            图片授权协议\n\n";

                document.Add(new Paragraph(text, font));

                //<appSettings>

                // <add key="TxtFilePath" value="config/pubcode/xieyi.txt"/>

                //<!-- 在WEBCOFIG里面加上的节点( value值是WebUI下的config/pubcode/xieyi.txt)这样的好处是:如果TXT的名称有改动,直接更改webconfig就行了 -->

                //<appSettings>

                TxtFilePath = AppDomain.CurrentDomain.BaseDirectory.ToString() + ConfigurationSettings.AppSettings["TxtFilePath"];

                font = new Font(bfSun, 10);

                text = ReadXieyi(TxtFilePath); //(@"C:\xieyi.txt");读取TXT文件的路径" 图片授权TXT文件协议内容";

                document.Add(new Paragraph(text, font));

                //插入图片

           string strCatalogId;

                DataTable dt = Online.Business.Production.bizDownPro.GetCatalogID(_pic_id);

                strCatalogId = dt.Rows[0][0].ToString();

                string FileNameUrl = "" + strCatalogId.ToLower() + "/thu/" + _pic_id.ToLower() + ".jpg";// "west004/thu/babf00254.jpg";//图片所在路径

                iTextSharp.text.Image jpeg = iTextSharp.text.Image.getInstance(new Uri(FileNameUrl));

                document.Add(new Paragraph("\n\n授权图片：", font));

                document.Add(jpeg);

                //插入图片编号

                document.Add(new Paragraph("\n图片编号:"+ _pic_id, font));

                string ActivateCode;

                ActivateCode = _pic_id + Online.WebUI.AccountController.LoginName; //用图片编号加上登陆名生成MD5编码,只取前25位

                string Md5Code;

                Md5Code = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(ActivateCode, "MD5").ToLower().Substring(0, 20); //加密MD5，只取前20位//"QJ-QQQQW-EEEER-TTTTY-UUUUN";

                string code;

                code = Md5Code.Substring(0, 5);//每5位之间用"-"分开

                code = code + "-" + Md5Code.Substring(5, 5);

                code = code + "-" + Md5Code.Substring(10, 5);

                code = code + "-" + Md5Code.Substring(15, 5);

                code = "QJ-" + code.ToString().ToUpper();

                document.Add(new Paragraph("\n授权码："+ code, font));//code是授权码

            }

            catch (DocumentException de)

            {

                Response.Write(de.Message);

            }

            catch (IOException ioe)

            {

                Response.Write(ioe.Message);

            }

            document.Close();

        }

#endregion

//按钮事件

        protected void Button2_Click(object sender, EventArgs e)

        {

            string name = Online.WebUI.AccountController.LoginName + "_" + _pic_id + ".pdf";

            SavePdfPath = AppDomain.CurrentDomain.BaseDirectory.ToString() + ConfigurationSettings.AppSettings["SavePdfPath"] + name;

            if (!File.Exists(SavePdfPath.ToString()))

            {

                zscsc();//创建PDF文档

                ReadDownData();//下载TXT文件

            }

            else

            {

                ReadDownData();//下载PDF文件

            }

        }

        //读取TXT文件并下载 PDF文件

        public void ReadDownData()

        {

            string name = Online.WebUI.AccountController.LoginName + "_" + _pic_id + ".pdf";

            SavePdfPath = AppDomain.CurrentDomain.BaseDirectory.ToString() + ConfigurationSettings.AppSettings["SavePdfPath"] + name;

            //读取文件，并写入到客户端响应

            FileStream fs = new FileStream(SavePdfPath.ToString(), FileMode.Open, FileAccess.Read);

            byte[] b = new Byte[fs.Length];

            fs.Read(b, 0, b.Length);

            fs.Flush();

            fs.Close();

            //File.Delete(filename.ToString()); 下载之后不执行删除

        Response.Clear();

            Response.ClearHeaders();

            Response.Buffer = false;

            Response.ContentType = "application/octet-stream";//ContentType;

            Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(name, System.Text.Encoding.UTF8));

            Response.AppendHeader("Content-Length", b.Length.ToString());

            Response.OutputStream.Write(b, 0, b.Length);

            Response.Flush();

            Response.End();

        }

转载 http://www.idai.com.cn/blog/article.asp?id=489