// 最新的导出文档方法 说明：参数 dt 可以是Html字符串 public void ExportToExcel(string FieldType, string FileName, string dt)        {            System.Web.HttpContext.Current.Response.Charset = "utf-8";            System.Web.HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(FileName, System.Text.Encoding.UTF8).ToString());            System.Web.HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");            System.Web.HttpContext.Current.Response.ContentType = FieldType;            StringWriter tw = new StringWriter();            System.Web.HttpContext.Current.Response.Output.Write(dt);            System.Web.HttpContext.Current.Response.Flush();            System.Web.HttpContext.Current.Response.End();        }