wanyue_app/app/common/File.php

<?php

namespace app\common;

//use Barryvdh\DomPDF\Facade\Pdf;
use Dompdf\Dompdf;

class File
{
    public static function exportPdf($content, $fileName)
    {
        $dompdf = new Dompdf();
        $dompdf->loadHtml($content);
        $dompdf->setPaper('A4', 'portrait');
        $dompdf->render();
        $pdfData = $dompdf->output();

        $savePath = public_path('storage/files/') . date('Ymd') . '/pdf';
        if (!is_dir($savePath)) {
            mkdir($savePath,0777,true);
        }
        $filePath = $savePath .'/'. $fileName;
        file_put_contents($filePath, $pdfData);

        return response()->file($filePath);
    }
}