mvc导出EXCEL

  /// <summary>
        /// 导出EXCEL
        /// </summary>
        /// <returns></returns>
        public ActionResult ExportExcel(FormCollection form)
        {


            //var sbHtml = new StringBuilder();
            //sbHtml.Append("<table border='1' cellspacing='0' cellpadding='0'>");
            //sbHtml.Append("<tr>");
            //var lstTitle = new List<string> { "编号", "姓名", "年龄", "创建时间" };
            //foreach (var item in lstTitle)
            //{
            //    sbHtml.AppendFormat("<td style='font-size: 14px;text-align:center;background-color: #DCE0E2; font-weight:bold;' height='25'>{0}</td>", item);
            //}
            //sbHtml.Append("</tr>");

            //for (int i = 0; i < 1000; i++)
            //{
            //    sbHtml.Append("<tr>");
            //    sbHtml.AppendFormat("<td style='font-size: 12px;height:20px;'>{0}</td>", i);
            //    sbHtml.AppendFormat("<td style='font-size: 12px;height:20px;'>屌丝{0}号</td>", i);
            //    sbHtml.AppendFormat("<td style='font-size: 12px;height:20px;'>{0}</td>", new Random().Next(20, 30) + i);
            //    sbHtml.AppendFormat("<td style='font-size: 12px;height:20px;'>{0}</td>", DateTime.Now);
            //    sbHtml.Append("</tr>");
            //}
            //sbHtml.Append("</table>");
            //byte[] fileContents = Encoding.UTF8.GetBytes(sbHtml.ToString());
            //var fileStream = new MemoryStream(fileContents);
            //return File(fileStream, "application/ms-excel", "fileStream.xls");

            //获取查询后条件的数据
            var query = from s in iWorkOrderService.Search(c => true)
                        where
                       (string.IsNullOrEmpty(form["hid"]) ? true : s.Id == form["hid"]) &&
                     (string.IsNullOrEmpty(form["hState"]) ? true : s.State.Contains(form["hState"])) &&
                    (string.IsNullOrEmpty(form["hType"]) ? true : s.Type.Contains(form["hType"])) &&
                  (string.IsNullOrEmpty(form["hPhone"]) ? true : s.Phone.Contains(form["hPhone"])) &&
                  (string.IsNullOrEmpty(form["hService"]) ? true : s.Service.Contains(form["hService"])) &&
                        (string.IsNullOrEmpty(form["hProcessingMode"]) ? true : s.ProcessingMode.Contains(form["hProcessingMode"])) &&
                        (string.IsNullOrEmpty(form["hProductId"]) ? true : s.ProductId == int.Parse(form["hProductId"])) &&
                      (string.IsNullOrEmpty(form["hCstart"]) && string.IsNullOrEmpty(form["hCend"]) ? true : DateTime.Parse(s.CreateTime) >= DateTime.Parse(form["hCstart"]) && DateTime.Parse(s.CreateTime) <= DateTime.Parse(form["hCend"])) &&
                    (string.IsNullOrEmpty(form["hAstart"]) && string.IsNullOrEmpty(form["hAend"]) ? true : DateTime.Parse(s.ProcessingTime) >= DateTime.Parse(form["hAstart"]) && DateTime.Parse(s.ProcessingTime) <= DateTime.Parse(form["hAend"]))

                        select new
                        {
                            s.Id,
                            s.Type,
                            s.SIM,
                            s.Product.Name,
                            s.Terminal,
                            s.Service,
                            s.Quantity,
                            s.Company,
                            s.Contact,
                            s.Sex,
                            s.Phone,
                            s.ProblemDescription,
                            s.Attachment,
                            s.ProcessingMode,
                            s.SI,
                            s.Suggestion,
                            s.State
                        };



            #region MyRegion
            System.Web.UI.WebControls.DataGrid dgExport = null;

            // 当前对话  

            System.Web.HttpContext curContext = System.Web.HttpContext.Current;

            // IO用于导出并返回excel文件  

            System.IO.StringWriter strWriter = null;

            System.Web.UI.HtmlTextWriter htmlWriter = null;

            string filename = DateTime.Now.Year + "_" + DateTime.Now.Month + "_" + DateTime.Now.Day + "_"

            + DateTime.Now.Hour + "_" + DateTime.Now.Minute;

            byte[] str = null;



            // 设置编码和附件格式

            curContext.Response.Charset = "GB2312";

            Response.AppendHeader("Content-Disposition", "attachment;filename=" + filename + ".xls");

            curContext.Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");//设置输出流为简体中文

            curContext.Response.ContentType = "application/vnd.ms-excel";

            //System.Text.Encoding.UTF8;

            // 导出excel文件  

            strWriter = new System.IO.StringWriter();

            htmlWriter = new System.Web.UI.HtmlTextWriter(strWriter);



            // 为了解决dgData中可能进行了分页的情况，需要重新定义一个无分页的DataGrid  

            dgExport = new System.Web.UI.WebControls.DataGrid();

            dgExport.DataSource = query;// db.WorkOrders.ToList();

            dgExport.AllowPaging = false;

            dgExport.DataBind();

            dgExport.RenderControl(htmlWriter);

            // 返回客户端  

            str = System.Text.Encoding.UTF8.GetBytes(strWriter.ToString());


            return File(str, "attachment;filename=" + filename + ".xls");
            #endregion

        }