多码识别双11优惠活动

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>二维码扫描</title>
</head>
<body>
    <video id="preview" width="300" height="200" autoplay></video>
    <button id="scan">开始扫描</button>
    <script src="https://cdn.jsdelivr.net/npm/quagga@0.12.1/dist/quagga.min.js"></script>
    <script>
        document.getElementById('scan').addEventListener('click', function() {
            Quagga.init({
                inputStream : {
                    name : "Live",
                    type : "LiveStream",
                    target: document.querySelector('#preview'),
                    constraints: {
                        width: {min: 640},
                        height: {min: 480},
                        facingMode: "environment" // 使用后置摄像头
                    },
                },
                decoder : {
                    readers : ["code_128_reader"] // 支持的码类型
                }
            }, function(err) {
                if (err) {
                    console.log(err);
                    return;
                }
                Quagga.start();
            });

            Quagga.onDetected(function(result) {
                console.log("Barcode detected and processed : ", result.codeResult.code);
                alert("识别到的优惠码是: " + result.codeResult.code);
                Quagga.stop();
            });
        });
    </script>
</body>
</html>