通过动态插入<script>到页面，src的地址里包含返回执行函数callback参数，请求的页面操作函数并带有数据callback(data)
<html>
<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type" />
<title>js跨域请求问题</title>
<meta content="IE=7" http-equiv="x-ua-compatible" />
</head>
<body>
<!-- main -->
<div id="main">
<input type="button" οnclick="get()" class="apibtn" value="查看结果" />
</div>
<div id="result" style="word-break: break-all;">
</div>
<script type="text/javascript">
var fn = {};
function load_script(xyUrl, callback) {
var head = document.getElementsByTagName('head')[0];
var script = document.createElement('script');
script.type = 'text/javascript';
script.src = xyUrl;
//借鉴了jQuery的script跨域方法
script.onload = script.onreadystatechange = function () {
if ((!this.readyState || this.readyState === "loaded" || this.readyState === "complete")) {
callback && callback();
// Handle memory leak in IE
script.onload = script.onreadystatechange = null;
if (head && script.parentNode) {
head.removeChild(script);
}
}
};
// Use insertBefore instead of appendChild to circumvent an IE6 bug.
head.insertBefore(script, head.firstChild);
}
function get() {
//debugger;
var callbackName = 'cbk_' + Math.round(Math.random() * 10000); //随机函数名
var xyUrl = "http://localhost/api/get_cate_nums.php?cityid=2419&callback=fn." + callbackName;
//动态创建script标签
load_script(xyUrl);
fn[callbackName] = function (xyResult) {
//debugger;
delete fn[callbackName]; //调用完需要删除改函数
callback && callback(xyResult);
}
}
function callback(xyResult) {
document.getElementById("result").innerHTML = "返回结果：" + xyResult;
}
</script>
</body>
</html>
对网上的代码做了些修改