前端监听网络变化和获取网速navigator.connection.downlink
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<script>
console.log('当前是否联网',navigator.onLine)
console.log('网速',navigator.connection.downlink,'MB/s')
window.addEventListener("online", () => {
console.log('网络已连接')
});
window.addEventListener("offline", () => {
console.log('网络已断开')
});
</script>
</body>
</html>
