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                <!DOCTYPE html>
<html lang="en">
        <meta charset="UTF-8" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
            img {
                width: 100%;
                height: 300px;
        <div id="app">
            <p v-for="item in imgs" :key="item">
                <img v-lazyload="item">
    <script src=""></script>
        Vue.directive("lazyload", {
            // 指令的定义
            bind: function(el, binding) {
                let lazyImageObserver = new IntersectionObserver((entries, observer) => {
                    entries.forEach((entry, index) => {
                        let lazyImage =;
                        // 相交率,默认是相对于浏览器视窗
                        if(entry.intersectionRatio > 0) {
                            lazyImage.src = binding.value;
                            // 当前图片加载完之后需要去掉监听

        var app = new Vue({
            el: "#app",
            data: {
                imgs: [