<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
div {
position: absolute;
left: 0;
width: 100px;
height: 100px;
background-color: pink;
}
span {
position: absolute;
left: 0;
top: 200px;
display: block;
width: 150px;
height: 150px;
background-color: purple;
}
</style>
</head>
<body>
<button class="btn500">点击到500</button>
<button class="btn800">点击到800</button>
<span></span>
<script>
function animate(obj, target, callback) {
clearInterval(obj.timer);
obj.timer = setInterval(function() {
var step = (target - obj.offsetLeft) / 10;
step = step > 0 ? Math.ceil(step) : Math.floor(step);
if (obj.offsetLeft == target) {
clearInterval(obj.timer);
if (callback) {
callback();
}
}
obj.style.left = obj.offsetLeft + step + 'px';
}, 15);
}
var span = document.querySelector('span');
var btn500 = document.querySelector('.btn500');
var btn800 = document.querySelector('.btn800');
btn500.addEventListener('click', function() {
animate(span, 500, function() {
span.style.backgroundColor = 'green';
});
})
btn800.addEventListener('click', function() {
animate(span, 800, function() {
span.style.backgroundColor = 'red';
});
})
</script>
</body>
</html>
