web前端页面中异步使用百度地图API

<div id="allmap"></div>

 1 //百度地图API功能
 2 function loadJScript() {
 3 var script = document.createElement("script");
 4 script.type = "text/javascript";
 5 script.src = "http://api.map.baidu.com/api?v=2.0&ak=8ni9BKv4NW6uDu5LUrRKCuCGp4RREX3g&callback=init";
 6 document.body.appendChild(script);
 7 }
 8 
 9 function init() {
10 var map = new BMap.Map("allmap"); // 创建Map实例
11 var point = new BMap.Point(116.293088,39.830886); // 创建点坐标
12 map.centerAndZoom(point, 18);
13 map.enableScrollWheelZoom(); //启用滚轮放大缩小
14 var marker = new BMap.Marker(point);
15 map.addOverlay(marker); // 将标注添加到地图中
16 marker.setAnimation(BMAP_ANIMATION_BOUNCE); //跳动的动画
17 
18 }
19 window.onload = loadJScript; //异步加载地图