asp.net 生成word,处理图片,富文本框内容图片处理

//基本导出方法
public void Download()
        {
            Random rd = new Random();
            string fileName = DateTime.Now.ToString("yyyyMMddhhmm") + rd.Next() + ".doc";
            //存储路径
            string path = Server.MapPath(fileName);
            //创建字符输出流
            StreamWriter sw = new StreamWriter(path, true, System.Text.UnicodeEncoding.UTF8);
            //需要导出的内容
           // string str = "<html><head><title>无标题文档</title></head><body>这里放从数据库导出的word文档内容</body></html>";
            string str = "";
            str += "<html><head><title>无标题文档</title></head><body>";
            str += "<div>阅读报表</div>";
            str += "<table border='1'><tr>";
            str += "<td>20000</td>";
            str += "<td>10000</td></tr><tr>";
            str += "<td>30000</td>";
            str += "<td>30000</td><tr>";
            str += "</table></body></html>";
            //写入
            sw.Write(str);
            sw.Close();
            Response.Clear();
            Response.Buffer = true;
            this.EnableViewState = false;
            Response.Charset = "utf-8";
            Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8));
            Response.ContentType = "application/octet-stream";
            Response.WriteFile(path);
            Response.Flush();
            Response.Close();
            Response.End();
        }

 //图片处理方法 图片转字节 base64 放到img src 中 如 <img src="data:image/jpeg;base64,ImgToBase64String(string Imagefilename)) /> 
   private string ImgToBase64String(string Imagefilename)
        {
            string result = "";
            try
            {
                using (FileStream fs = new FileStream(Imagefilename,FileMode.Open,FileAccess.Read))
                {
                    byte[] byteArray = new byte[fs.Length];
                    fs.Read(byteArray, 0, byteArray.Length);
                    result = Convert.ToBase64String(byteArray);
                }
            }
            catch
            {
                result = "";
            }
            return result;
        }

 /// <summary>
        /// 富文本框 内容里面的 图片处理
        /// </summary>
        /// <param name="text"></param>
        /// <returns></returns>
        public string ContentHandler(string text)
        {
            if (string.IsNullOrEmpty(text))
            {
                return text;
            }

            HtmlDocument document = new HtmlDocument();
            document.LoadHtml(text);
            var imgNodes = document.DocumentNode.SelectNodes("//img");
            if (imgNodes != null)
            {
                Parallel.ForEach(imgNodes, imgNode =>
                {
                    var src = imgNode.GetAttributeValue("src", "");
                    if (!string.IsNullOrEmpty(src))
                    {
                        var filename = context.Server.MapPath(src);
                        if (File.Exists(filename))
                        {
                            imgNode.SetAttributeValue("src", "data:image/jpeg;base64," + ImgToBase64String(filename));

                        }
                    }
                });
            }

            return document.DocumentNode.OuterHtml;

        }