如何在函数中使用PHPSpreadsheet类

require_once 'path/to/vendor/autoload.php';
use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\IOFactory;

$sheet = $spreadsheet->getActiveSheet();
$sheet->setCellValue('A1', 'Hello');
$sheet->setCellValue('B1', 'World!');

$style = [
    'font' => [
        'bold' => true,
        'color' => ['rgb' => 'FF0000'],
    ],
];
$sheet->getStyle('A1')->applyFromArray($style);

$data = [
    ['Name', 'Age', 'City'],
    ['John Doe', 25, 'New York'],
    ['Jane Smith', 30, 'London'],
];
$sheet->fromArray($data, null, 'A2');

require_once 'path/to/vendor/autoload.php';
use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\IOFactory;

function generateExcel() {
    $spreadsheet = new Spreadsheet();
    $sheet = $spreadsheet->getActiveSheet();

    // 添加数据到单元格
    $sheet->setCellValue('A1', 'Hello');
    $sheet->setCellValue('B1', 'World!');

    // 设置单元格样式
    $style = [
        'font' => [
            'bold' => true,
            'color' => ['rgb' => 'FF0000'],
        ],
    ];
    $sheet->getStyle('A1')->applyFromArray($style);

    // 创建表格
    $data = [
        ['Name', 'Age', 'City'],
        ['John Doe', 25, 'New York'],
        ['Jane Smith', 30, 'London'],
    ];
    $sheet->fromArray($data, null, 'A2');

    // 保存或输出Excel文件
    $writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
    $writer->save('path/to/save.xlsx');
}

generateExcel();