Image预加载
<div class="hidden">
???<script type="text/javascript">
???????
???????????var images = new Array()
???????????function preload() {
???????????????for (i = 0; i < preload.arguments.length; i++) {
???????????????????images[i] = new Image()
???????????????????images[i].src = preload.arguments[i]
???????????????}
???????????}
???????????preload(
???????????????"./images/icon-1.png",
???????????????"./images/icon-2.png",
???????????????"./images/icon-4.png",
???????????????"./images/icon-5.png",
???????????????"./images/icon-3.png",
???????????????"./images/icon-6.png",
???????????????"./images/icon-7.png",
???????????????"./images/icon-8.png",
???????????????"./images/icon-9.png",
???????????????"./images/icon-10.png",
???????????????"./images/icon-11.png",
???????????????"./images/icon-12.png",
???????????????"./images/icon-13.png",
???????????????"./images/icon-14.png",
???????????????"./images/icon-15.png",
???????????????"./images/icon-16.png",
???????????????"./images/icon-17.png",
???????????????"./images/icon-18.png",
???????????????"./images/icon-19.png",
???????????????"./images/icon-20.png",
???????????)
???</script>
</div>
JS
function loadScript(src,fn){
???var node = document.createElement("script");
???node.setAttribute(‘async‘,‘async‘);
var timeID
var supportLoad = "onload" in node
var onEvent = supportLoad ? "onload" : "onreadystatechange"
node[onEvent] = function onLoad() {
???if (!supportLoad && !timeID && /complete|loaded/.test(node.readyState)) {
???????timeID = setTimeout(onLoad)
???????return
???}
???if (supportLoad || timeID) {
???????clearTimeout(timeID)
???????fn(null,node);
???}
}
document.head.insertBefore(node, document.head.firstChild);
node.src=src;
node.onerror=function(e){
fn(e);
}
???}
???loadScript("test.js",fail);
CSS
function loadCss(src,fn){
???var node=document.createElement(‘link‘);
???node.rel=‘stylesheet‘;
???node.href=src;
???document.head.insertBefore(node,document.head.firstChild);
???if(node.attachEvent){
???node.attachEvent(‘onload‘, function(){fn(null,node)});
???}else{
??setTimeout(function() {
????????poll(node, fn);
??????}, 0); // for cache
???}
???function poll(node,callback){
???var isLoaded = false;
???if(/webkit/i.test(navigator.userAgent)) {//webkit
???????if (node[‘sheet‘]) {
???????isLoaded = true;
?????}
???}else if(node[‘sheet‘]){// for Firefox
???try{
???????if (node[‘sheet‘].cssRules) {
?????????isLoaded = true;
???????}
?????}catch(ex){
???????// NS_ERROR_DOM_SECURITY_ERR
???????if (ex.code === 1000) {
????????isLoaded = true;
???????}
???}
???}
???if(isLoaded){
???setTimeout(function(){
???callback(null,node);
???},1);
???}else{
???setTimeout(function(){
???poll(node,callback);
???},10);
???}
???}
???node.onLoad=function(){
???fn(null,node);
???}
???}
JS
function loadScript(src,fn) {
var node = document.createElement("script");
???node.setAttribute(‘async‘,‘async‘);
var timeID
var supportLoad = "onload" in node
var onEvent = supportLoad ? "onload": "onreadystatechange"
node[onEvent] = function onLoad() {
???if (!supportLoad && !timeID && /complete|loaded/.test(node.readyState)) {
???????timeID = setTimeout(onLoad)
???????return
}
if (supportLoad || timeID) {
clearTimeout(timeID)
???????fn(null,node);
}
}
document.head.insertBefore(node, document.head.firstChild);
node.src=src;
node.onerror=function(e) {
fn(e);
}
???}
JS、CSS、Image预加载
原文地址：https://www.cnblogs.com/xieyongbin/p/10027997.html