改写前：
百度地图中坐标转换的JavaScript API示例官方示例如下：
var points = [new BMap.Point(116.3786889372559,39.90762965106183),
new BMap.Point(116.38632786853032,39.90795884517671),
new BMap.Point(116.39534009082035,39.907432133833574),
new BMap.Point(116.40624058825688,39.90789300648029),
new BMap.Point(116.41413701159672,39.90795884517671)
]; //地图初始化
var bm = new BMap.Map("allmap");
bm.centerAndZoom(new BMap.Point(116.378688937,39.9076296510), 15); //坐标转换完之后的回调函数
translateCallback = function (data){
if(data.status === 0) {
for (var i = 0; i < data.points.length; i++) {
bm.addOverlay(new BMap.Marker(data.points[i]));
bm.setCenter(data.points[i]);
}
}
}
setTimeout(function(){
var convertor = new BMap.Convertor();
convertor.translate(points, 1, 5, translateCallback)
}, 1000);
改写后：
将上述代码改写为传统的JavaScript回调函数形式：
function translate(points,callback){
var convertor=new BMap.Convertor();
convertor.translate(points, 1, 5, callback)
translateCallback = function (data){
if(data.status === 0) {
var res=[]; //res用来存放转换后的points数组
for (var i = 0; i < data.points.length; i++) {
bm.addOverlay(new BMap.Marker(data.points[i]));
res.push(data.points[i]);
}
callback(res)
}
}
}
//再调用translate函数，
translate(points,function(data){
console.log(data); //data为转换后的points数组
})
改写后translate函数接受两个参数，第一个参数为原始的百度points数组，第二个参数传入一个回调函数。