string filename = Server.MapPath("../../../rektecweb/upload/") + DateTime.Now.ToString("yyyyMMddHHmmssfff") + "_" + FileUpload1.FileName; //获取文件后缀名 string type = filename.Substring(filename.LastIndexOf(".") + 1); if (type.ToLower() != "xls" && System.IO.Path.GetExten...