MutationObserver_API:    观察某一个元素的变化

// index.vue<template><div class="container"><Watermark text="版权所有" style="background: #28c848"><!-- 可给图片、视频、div...添加水印 --><div class="content"></div></Watermark><Watermark text="禁止转载" style="border: 1px solid #cacaca"><img :src="require('@/assets/xiaomi/pms_1605536123.55818348.jpg')" class="content"></img></Watermark></div>
</template><script>import Watermark from "./watermark.vue";export default {components: { Watermark },data() {return {};},methods: {},};
</script><style lang="scss" scoped>.container {width: 100%;display: flex;justify-content: space-around;}.content {width: 450px;height: 600px;}
</style>

// watermark.vue<template><div class=