图片懒加载效果
1.简单的图片懒加载效果代码
可复制使用 注意图片的src 你是否一致
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
img {
display: block;
margin: 200px auto;
}
</style>
</head>
<body>
<img src="./1.gif" data-imgurl="./1.gif" alt="">
<img src="./1.gif" data-imgurl="./1.jpg" alt="">
<img src="./1.gif" data-imgurl="./2.jpg" alt="">
<img src="./1.gif" data-imgurl="./3.jpg" alt="">
<script>
//逻辑 当图片的 offsettop < html.scrolltop+windowm.clientHeigt
//图片将要在 client可视区展示 要发请求加载图片
(function () {
window.onscroll = function () {
//获取位置
var imglist = document.querySelectorAll("img");
//划过去的高度
var crossHeight = document.documentElement.scrollTop;
//可视区高度
var look = window.innerHeight;
//添加事件
imglist.forEach((item, index) => {
// console.log(item.offsetTop);
console.log(crossHeight);
var bol = item.offsetTop < crossHeight + look
if (bol) {
console.log("好了");
item.src = item.getAttribute("data-imgurl")
}
})
}
})()
</script>
</body>
</html>