gvShowExport.AllowPaging = false; //清除分页
                    gvShowExport.AllowSorting = false; //清除排序
                    string sqlString = " select  *  from  dept_export  where  flag='" + flag + "'  and  addDate>='" + SearchTimeStart1.Text + "'  and  addDate<='" + SearchTimeEnd1.Text + "'";
                    gvShowExport.DataSource = DbHelperSQL.Query(sqlString);
                    gvShowExport.DataKeyNames = new String[] { "id" };
                    gvShowExport.Columns[8].Visible = false;
                    gvShowExport.DataBind();  //绑定gridview1数据源                  

                    Response.Clear();
                    Response.Buffer = true;
                    Response.Charset = "GB2312";
                    Response.AppendHeader("Content-Disposition", "attachment;filename=FileNew.xls"); //.xls的文件名可修改
                    Response.ContentEncoding = System.Text.Encoding.UTF8;
                    Response.ContentType = "application/ms-excel";      //设置输出文件类型为excel文件。  
                    System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
                    System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
                    gvShowExport.RenderControl(oHtmlTextWriter);
                    HttpContext.Current.Response.Write(oStringWriter.ToString());
                    HttpContext.Current.Response.Flush();
                    HttpContext.Current.Response.End();

                    gvShowExport.DataSource = DbHelperSQL.Query(sqlString);
                    gvShowExport.DataKeyNames = new String[] { "id" };
                    gvShowExport.AllowSorting = true; //恢复分页        
                    gvShowExport.AllowPaging = true;  //恢复排序
                    gvShowExport.DataBind(); //再次绑定