phpexcel写入追加已有的excel文件

/**
     * 在已有excel表中插入数据例子
     */

    public function readyExcel($filename){
        vendor("PHPExcel.PHPExcel");
        $inputFileName = $filename;//excel文件路径
        date_default_timezone_set('PRC');
        // 读取excel文件
        try {
            $inputFileType = PHPExcel_IOFactory::identify($inputFileName);
            $objReader = PHPExcel_IOFactory::createReader($inputFileType);
            $objPHPExcel = $objReader->load($inputFileName);
        } catch(Exception $e) {
            die('加载文件发生错误："'.pathinfo($inputFileName,PATHINFO_BASENAME).'": '.$e->getMessage());
        }
        $array = [
            ['A','B','C','D','E','F'],
            ['A1','B1','C1','D1','E1','F1'],
            ['A2','B2','C2','D2','E2','F2']
        ];
        $baseRow=17;      //指定插入到第17行后
        foreach($array as $index=>$dataRow){
            $row= $baseRow +$index;    //$row是循环操作行的行号
            $objPHPExcel->getActiveSheet()->insertNewRowBefore($row,1);  //在操作行的号前加一空行，这空行的行号就变成了当前的行号
            //对应的列都附上数据和编号
            $objPHPExcel->getActiveSheet()->setCellValue( 'A'.$row,$dataRow[0]);
            $objPHPExcel->getActiveSheet()->setCellValue( 'B'.$row,$dataRow[1]);
            $objPHPExcel->getActiveSheet()->setCellValue( 'C'.$row,$dataRow[2]);
            $objPHPExcel->getActiveSheet()->setCellValue( 'D'.$row,$dataRow[3]);
            $objPHPExcel->getActiveSheet()->setCellValue( 'E'.$row, $dataRow[4]);
            $objPHPExcel->getActiveSheet()->setCellValue( 'F'.$row, $dataRow[5]);
        }
        ob_end_clean();//清除缓存区，解决乱码问题
        header('Content-Type: application/vnd.ms-excel');
        header('Content-Disposition: attachment;filename="Bill.xls"');
        header('Cache-Control: max-age=0');
        $objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5');
        $objWriter->save('php://output');
        exit;
    }

　　https://my.oschina.net/luqiuren666/blog/3013101