另一种方法是将JS的Web Animations API与CSS结合使用。
例子
async function moveToPosition(el, durationInMs) {
return new Promise((resolve) => {
const animation = el.animate([{
opacity: '0'
},
{
transform: `translateY(${el.getBoundingClientRect().top}px)`
},
], {
duration: durationInMs,
easing: 'ease-in',
iterations: 1,
direction: 'normal',
fill: 'forwards',
delay: 0,
endDelay: 0
});
animation.onfinish = () => resolve();
});
}
async function fadeIn(el, durationInMs) {
return new Promise((resolve) => {
const animation = el.animate([{
opacity: '0'
},
{
opacity: '0.5',
offset: 0.5
},
{
opacity: '1',
offset: 1
}
], {
duration: durationInMs,
easing: 'linear',
iterations: 1,
direction: 'normal',
fill: 'forwards',
delay: 0,
endDelay: 0
});
animation.onfinish = () => resolve();
});
}
async function fadeInSections() {
for (const section of document.getElementsByTagName('section')) {
await fadeIn(section, 200);
}
}
window.addEventListener('load', async() => {
await moveToPosition(document.getElementById('headerContent'), 500);
await fadeInSections();
await fadeIn(document.getElementsByTagName('footer')[0], 200);
});
async function moveToPosition(el, durationInMs) {
return new Promise((resolve) => {
const animation = el.animate([{
opacity: '0'
},
{
transform: `translateY(${el.getBoundingClientRect().top}px)`
},
], {
duration: durationInMs,
easing: 'ease-in',
iterations: 1,
direction: 'normal',
fill: 'forwards',
delay: 0,
endDelay: 0
});
animation.onfinish = () => resolve();
});
}
async function fadeIn(el, durationInMs) {
return new Promise((resolve) => {
const animation = el.animate([{
opacity: '0'
},
{
opacity: '0.5',
offset: 0.5
},
{
opacity: '1',
offset: 1
}
], {
duration: durationInMs,
easing: 'linear',
iterations: 1,
direction: 'normal',
fill: 'forwards',
delay: 0,
endDelay: 0
});
animation.onfinish = () => resolve();
});
}
async function fadeInSections() {
for (const section of document.getElementsByTagName('section')) {
await fadeIn(section, 200);
}
}
window.addEventListener('load', async() => {
await moveToPosition(document.getElementById('headerContent'), 500);
await fadeInSections();
await fadeIn(document.getElementsByTagName('footer')[0], 200);
});
body,
html {
height: 100vh;
}
header {
height: 20%;
}
.text-center {
text-align: center;
}
.leading-none {
line-height: 1;
}
.leading-3 {
line-height: .75rem;
}
.leading-2 {
line-height: .25rem;
}
.bg-black {
background-color: rgba(0, 0, 0, 1);
}
.bg-gray-50 {
background-color: rgba(249, 250, 251, 1);
}
.pt-12 {
padding-top: 3rem;
}
.pt-2 {
padding-top: 0.5rem;
}
.text-lightGray {
color: lightGray;
}
.container {
display: flex;
/* or inline-flex */
justify-content: space-between;
}
.container section {
padding: 0.5rem;
}
.opacity-0 {
opacity: 0;
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<link rel="icon" href="/favicon.ico" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<meta name="description" content="Web site created using create-snowpack-app" />
<link rel="stylesheet" type="text/css" href="./assets/syles/index.css" />
</head>
<body>
<header class="bg-gray-50">
<div id="headerContent">
<h1 class="text-center leading-none pt-2 leading-2">Hello</h1>
<p class="text-center leading-2"><i>Ipsum lipmsum emus tiris mism</i></p>
</div>
</header>
<div class="container">
<section class="opacity-0">
<h2 class="text-center"><i>ipsum 1</i></h2>
<p>Cras purus ante, dictum non ultricies eu, dapibus non tellus. Nam et ipsum nec nunc vestibulum efficitur nec nec magna. Proin sodales ex et finibus congue</p>
</section>
<section class="opacity-0">
<h2 class="text-center"><i>ipsum 2</i></h2>
<p>Cras purus ante, dictum non ultricies eu, dapibus non tellus. Nam et ipsum nec nunc vestibulum efficitur nec nec magna. Proin sodales ex et finibus congue</p>
</section>
<section class="opacity-0">
<h2 class="text-center"><i>ipsum 3</i></h2>
<p>Cras purus ante, dictum non ultricies eu, dapibus non tellus. Nam et ipsum nec nunc vestibulum efficitur nec nec magna. Proin sodales ex et finibus congue</p>
</section>
</div>
<footer class="opacity-0">
<h1 class="text-center leading-3 text-lightGray"><i>dictum non ultricies eu, dapibus non tellus</i></h1>
<p class="text-center leading-3"><i>Ipsum lipmsum emus tiris mism</i></p>
</footer>
</body>
</html>
