npm install
npm run serve
npm install vue-lazyload --save
或使用 cdn 引入
<script src="https://unpkg.com/vue-lazyload/vue-lazyload.js"></script>
main.js 中引入插件
import Vue from "vue";
import App from "./App.vue";
import router from "./router";
import store from "./store";
import VueLazyload from "vue-lazyload"
// error:加载失败使用的图片
// loading: 加载中使用的图片
Vue.use(VueLazyload, {
error: 'http://a2.att.hudong.com/36/48/19300001357258133412489354717.jpg',
// loading: 'http://img.zcool.cn/community/0195f55972f18ca8012193a342310a.gif',
loading: require('./assets/lazy.gif') // 若为本地图片需要 reqyire 引入
})
Vue.config.productionTip = false;
new Vue({
router,
store,
render: h => h(App)
}).$mount("#app");
img 标签中,使用 v-lazy
替换 src
即可
<template>
<div class="home">
<div v-for="item in imgList">
<img class="img" v-lazy="item" />
</div>
</div>
</template>
思路:
- 为
img
标签添加属性src
中存储加载时的图片,data-src
里面存储真正的图片地址 - 通过监听页面的滚动事件,当
img
标签滚动到当前视图窗口时,使用data-src
中的地址替换src
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<script src="https://cdn.bootcss.com/jquery/2.1.0/jquery.min.js"></script>
<style>
.container {
max-width: 800px;
margin: 0 auto;
}
.container:after {
content: "";
display: block;
clear: both;
}
.container img {
width: 50%;
height: 260px;
float: left;
}
</style>
</head>
<body>
<div class="container">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img4.imgtn.bdimg.com/it/u=951914923,777131061&fm=26&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img1.imgtn.bdimg.com/it/u=637435809,3242058940&fm=26&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img1.imgtn.bdimg.com/it/u=3990342075,2367006974&fm=200&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img1.imgtn.bdimg.com/it/u=1813891576,1754763093&fm=26&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img4.imgtn.bdimg.com/it/u=2539922263,2810970709&fm=200&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img4.imgtn.bdimg.com/it/u=1878067600,3935137756&fm=200&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img3.imgtn.bdimg.com/it/u=85690711,3884201894&fm=26&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img2.imgtn.bdimg.com/it/u=3844233833,3942617167&fm=200&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img0.imgtn.bdimg.com/it/u=1846695025,2515725663&fm=26&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img3.imgtn.bdimg.com/it/u=346230831,1833217134&fm=200&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img5.imgtn.bdimg.com/it/u=3478148120,2683867435&fm=26&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img5.imgtn.bdimg.com/it/u=2298824648,1812234339&fm=200&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img2.imgtn.bdimg.com/it/u=4201594846,4178139206&fm=26&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img2.imgtn.bdimg.com/it/u=484389598,819397330&fm=200&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img1.imgtn.bdimg.com/it/u=3729466012,914166979&fm=26&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img2.imgtn.bdimg.com/it/u=354463615,3836278171&fm=200&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img5.imgtn.bdimg.com/it/u=1831250492,3489827059&fm=200&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img1.imgtn.bdimg.com/it/u=779005622,2247570143&fm=200&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img1.imgtn.bdimg.com/it/u=1968229118,3512711019&fm=26&gp=0.jpg">
<img src="http://s4.sinaimg.cn/mw690/006uWPTUgy72CNFYNjB93&690" alt="1"
data-src="http://img2.imgtn.bdimg.com/it/u=1088428253,1150170159&fm=200&gp=0.jpg">
</div>
<script>
// 一开始没有滚动的时候,出现在视窗中的图片也会加载
start();
// 当页面开始滚动的时候,遍历图片,如果图片出现在视窗中,就加载图片
var clock; //函数节流
$(window).on('scroll', function () {
if (clock) {
clearTimeout(clock);
}
clock = setTimeout(function () {
start()
}, 200)
})
function start() {
$('.container img').not('[data-isLoading]').each(function () {
if (isShow($(this))) {
loadImg($(this));
}
})
}
// 判断图片是否出现在视窗的函数
function isShow($node) {
return $node.offset().top <= $(window).height() + $(window).scrollTop();
}
// 加载图片的函数,就是把自定义属性data-src 存储的真正的图片地址,赋值给src
function loadImg($img) {
$img.attr('src', $img.attr('data-src'));
// 已经加载的图片,我给它设置一个属性,值为1,作为标识
// 弄这个的初衷是因为,每次滚动的时候,所有的图片都会遍历一遍,这样有点浪费,所以做个标识,滚动的时候只遍历哪些还没有加载的图片
$img.attr('data-isLoading', 1);
}
</script>
</body>
</html>