异步加载script实现jsonp效果
function scriptLoad(src,callback){ var script=document.createElement('script'); scriptOnload(script,callback); script.src=src; document.getElementsByTagName('head')[0].appendChild(script); function scriptOnload(node,callback) { node.onload = node.onerror = node.onreadystatechange = function() { if (/loaded|complete|undefined/.test(node.readyState)) { //限制只执行一次,避免IE浏览器因readystate的变化而执行多次 node.onload = node.onerror = node.onreadystatechange = null; //执行完成后删除该临时script node.parentNode.removeChild(node); //控制内存泄露,删除变量 node = undefined; //执行回调函数 callback() } } } }