# requestIdleCallback
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<style>
.show-info {
font-size: 14px;
line-height: 2;
}
.btn-default {
display: inline-block;
padding: 6px 12px;
margin-bottom: 0;
font-size: 14px;
font-weight: 400;
line-height: 1.42857143;
text-align: center;
white-space: nowrap;
vertical-align: middle;
-ms-touch-action: manipulation;
touch-action: manipulation;
cursor: pointer;
-webkit-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;
background-image: none;
border: 1px solid transparent;
border-radius: 4px;
color: #333;
background-color: #fff;
border-color: #ccc;
margin-bottom: 10px;
}
.btn-default:hover {
background-color: #ededed;
}
.c-f00 {
color: #f00;
}
</style>
</head>
<body>
<div class="m10">
<h1>requestIdleCallback测试(timeout=100)</h1>
<div class="blank-area">
<p>rIC的复杂回调与复杂回调的优化</p>
<div>
<a id="btn1" class="btn-default" href="javascript:;">rIC复杂回调</a>
<a id="btn2" class="btn-default" href="javascript:;"
>rIC复杂回调(分段回调)</a
>
</div>
<p id="info" class="show-info"></p>
</div>
</div>
<script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.5.1/jquery.js"></script>
<script>
var requestId = 0,
info = $("#info"),
html = "",
secs = 0;
if (!("requestIdleCallback" in window)) {
info.html(
"您的浏览器还不支持requestIdleCallback方法哦，建议使用chrome浏览器尝试~"
);
}
var rAF = (function () {
return (
window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
function (callback) {
window.setTimeout(callback, 1000 / 60);
}
);
})();
function add(t, className) {
info.append(
'<span class = "' + (className || "") + '">' + t + "</span><br/>"
);
}
function rIC(cb) {
requestId = requestIdleCallback(cb);
}
function cb1(deadline) {
var i = 0,
len = 10000,
secs = new Date().getTime();
add("rIC回调中，执行了一个" + len + "长度的循环");
for (i; i < len; i++) {
if ((i * 10) % len == 0) {
add("rIC 回调中，第" + i + "次循环", "c-f00");
}
console.log("i=" + i);
}
add("rIC消耗时间=" + (new Date().getTime() - secs), "c-f00");
}
function _cb1() {
var i = 0,
len = 5;
info.html("");
function _s() {
if (i < len) {
add("rAF 循环次数 i=" + i);
rAF(_s);
i++;
}
}
rIC(cb1);
rAF(_s);
}
$("#btn1").on("click", _cb1);
function cb2(deadline) {
var i = 0,
len = 1000,
secs = new Date().getTime();
add("rIC回调中，执行了一个" + len + "长度的循环");
function _s(deadline) {
//表示该帧还有剩余时间
for (i; i < len; i++) {
if (deadline.timeRemaining() > 0) {
console.log("i=" + i);
if ((i * 10) % len == 0) {
add("rIC 回调中，第" + i + "次循环", "c-f00");
}
} else {
rIC(_s);
break;
}
}
}
_s(deadline);
}
function _cb2() {
var i = 0,
len = 5;
info.html("");
function _s() {
if (i < len) {
add("rAF 循环次数 i=" + i);
rAF(_s);
i++;
}
}
rIC(cb2);
rAF(_s);
}
$("#btn2").on("click", _cb2);
</script>
</body>
</html>
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