监听dom

let MutationObserver = window.MutationObserver || window.WebKitMutationObserver || window.MozMutationObserver;
const mutation = new MutationObserver(function(mutationRecoards, observer) {
})
// 对观察者添加需要观察的元素，并设置需要观察元素的哪些方面
mutation.observe(document.getElementsByTagName('body')[0], {
attributes: true,
childList: true,
});

https://blog.csdn.net/qq_35385241/article/details/121989261