phpspreadsheet composer未安装

{
    "require": {
        "phpoffice/phpspreadsheet": "^1.0"
    }
}

composer install

<?php
require 'vendor/autoload.php';

use PhpOffice\PhpSpreadsheet\IOFactory;

// 读取Excel文件
$spreadsheet = IOFactory::load('path/to/your/excel/file.xlsx');
$worksheet = $spreadsheet->getActiveSheet();
$data = $worksheet->getCell('A1')->getValue();

// 写入Excel文件
$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
$worksheet = $spreadsheet->getActiveSheet();
$worksheet->setCellValue('A1', 'Hello World!');
$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
$writer->save('path/to/save/excel/file.xlsx');