IE下PHPEXCEL乱码问题

//输出到临时缓冲区  提供下载header("Content-type:application/vnd.ms-excel;charset=UTF-8");$ua = $_SERVER["HTTP_USER_AGENT"];$encoded_filename = urlencode($this->fileName);$encoded_filename = str_replace("+", "%20", $encoded_filename);header('Content-Type: application/octet-stream');if (preg_match("/Triden/",$ua)) { //IE    header('Content-Disposition: attachment; filename="' . $encoded_filename . '"');} else if (preg_match("/Firefox/", $ua)) {    header('Content-Disposition: attachment; filename*="utf8\'\'' . $this->fileName . '"');} else {    header('Content-Disposition: attachment; filename="' . $this->fileName . '"');}header('Cache-Control: max-age=0');$objWriter = \PHPExcel_IOFactory::createWriter ( $this->excelObj, 'Excel5' );$objWriter->save ( 'php://output' );