1 var addHandler = document.body.addEventListener ?
2 function(target, eventType, handler) {
3 target.addEventListener(eventType, handler,
false);
4 } :
function(target, eventType, handler) {
5 target.attachEvent("on" +
eventType, handler);
6 };
7
8 var removeHandler = document.body.removeEventListener ?
9 function(target, eventType, handler) {
10 target.removeEventListener(eventType, handler,
false);
11 } :
function(target, eventType, handler) {
12 target.detachEvent("on" +
eventType, handler);
13 };
预加载适用于一个函数马上要被用到，并且在整个页面的生命周期中频繁出现的场合。
转载于:https://www.cnblogs.com/qzsonline/archive/2012/07/02/2573451.html
