phpspreadsheet导出excel自动获得列，数字下标

安装composer require phpoffice/phpspreadsheetuse PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
use PhpOffice\PhpSpreadsheet\Style\Border;$spreadsheet = new Spreadsheet();
$sheet = $spreadsheet->getActiveSheet();//从65开，65是第1列，66是第二列，2是第二行
$sheet->setCellValue(strtoupper(chr(65)) . '1', '大得');
$sheet->setCellValue(strtoupper(chr(66)) . '1', '大得');
$sheet->setCellValue(strtoupper(chr(66)) . '2', '大2');header('Content-Type: application/vnd.ms-excel');
header('Content-Disposition: attachment;filename=/www/wwwroot/swoole/erp-test-zhoao2/excel/666.xlsx"');
header('Cache-Control: max-age=0');
$writer = new Xlsx($spreadsheet);
$date = date("Ymd");
$Absolute_Path=$_SERVER['SCRIPT_FILENAME'];
$user_path = substr($Absolute_Path,0,-9)."storage/cdjdade/{$date}";//保存路径
if(!is_dir($user_path)){mkdir($user_path);
}
$writer->save($user_path.'/666.xlsx');
//删除清空：
$spreadsheet->disconnectWorksheets();
unset($spreadsheet);

报错Invalid cell coordinate [1，下标超过26个字母

$spreadsheet = new Spreadsheet();$sheet = $spreadsheet->getActiveSheet();$sheet->setCellValue(strtoupper(chr(65)) . '1', '部门');$sheet->setCellValue(strtoupper(chr(66)) . '1', '员工');$sheet->setCellValue(strtoupper(chr(67)) . '1', '入职日期');$sheet->setCellValue(strtoupper(chr(68)) . '1', '岗位');$sheet->setCellValue(strtoupper(chr(69)) . '1', '职位');for ($i=1;$i<=$day;$i++){$s = round(69+$i);if($s<91){$sheet->setCellValue(strtoupper(chr($s)) . '1', $i);}else{//超过26个字母，在此超过B$s = $s-26;$sheet->setCellValue(chr(ord("A")).strtoupper(chr($s)) . '1', $i);}}header('Content-Type: application/vnd.ms-excel');header('Content-Disposition: attachment;filename=/www/wwwroot/swoole/erp-test-zhoao2/excel/666.xlsx"');header('Cache-Control: max-age=0');$writer = new Xlsx($spreadsheet);$date = date("Ymd");$Absolute_Path=$_SERVER['SCRIPT_FILENAME'];$user_path = substr($Absolute_Path,0,-9)."storage/cdjdade/{$date}";//保存路径if(!is_dir($user_path)){mkdir($user_path);}$dates = date("YmdHis");$writer->save($user_path."/$dates.xlsx");//删除清空：$spreadsheet->disconnectWorksheets();unset($spreadsheet);