本文实例讲述了异步安全加载javascript文件的方法。分享给大家供大家参考。具体如下：
使用方法：
(function() { __safeloadscript(http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js, function() { alert(jquery); });})();
javascript实现代码：
window.__safeloadscript = function(src, callback) { function addevent(obj, type, fn) { if (obj.attachevent) { obj['e' + type + fn] = fn; obj[type + fn] = function() { obj['e' + type + fn](window.event); } obj.attachevent('on' + type, obj[type + fn]); } else obj.addeventlistener(type, fn, false); } function async_load(src, callback) { var s = document.createelement('script'); s.type = 'text/javascript'; s.async = true; var protocol = ((https: == document.location.protocol) ? https:// : http://); s.src = protocol + src; var x = document.getelementsbytagname('script')[0]; x.parentnode.insertbefore(s, x); s.onload = s.onreadystatechange = function() { if(callback && (!this.readystate || this.readystate == loaded || this.readystate == complete)) { callback(); } }; } addevent(window, load, function() { async_load(src, callback); });};
希望本文所述对大家的javascript程序设计有所帮助。