我正在开发一个名为 Web Bluetooth 的 PWA,并尝试仅扫描过滤信标并在配对后显示其uuid
、major
、minor
值。所以这里是脚本代码:
<script>
function onClickButton() {
var known_service = "battery_service";
return navigator.bluetooth.requestDevice({
filters: [{ services: [known_service] }]
})
.then(() => {
navigator.bluetooth.addEventListener('advertisementreceived', event => {
var rssi = event.rssi;
var appleData = event.manufacturerData.get(0x004C);
if (appleData.byteLength != 23 ||
appleData.getUint16(0, false) !== 0x0215) {
console.log({ isBeacon: false });
}
var uuidArray = new Uint8Array(appleData.buffer, 2, 16);
var major = appleData.getUint16(18, false);
var minor = appleData.getUint16(20, false);
var txPowerAt1m = -appleData.getInt8(22);
console.log({
isBeacon: true,
uuidArray,
major,
minor,
pathLossVs1m: txPowerAt1m - rssi
});
});
})
}
</script>
当我运行代码时,我收到错误消息
无法读取 null 的属性“addEventListener”。
我已经尝试过诸如添加之类的建议window.onload = function
,但它不起作用。所以请建议我该怎么做?谢谢你。