人生中第一次调用API开放平台（以前也很少需要用到，感觉很高大上），真的感受到了什么叫做方便，什么叫做强大。以前总是把问题想得很复杂，今天花了半天的时间试了下调用百度地图API，显示定位信息、热力图信息、路径导航等问题处理起来真的很方便。（有点激动，多了点废话）
可以实现的功能非常多，这里给出一个显示热力图的示意图，最上面的Title“百度地图演示系统”是我自己以图片的形式添加的，因此这里需要更改为你自己的本地图片。
样例源码如下：
新建文件demo.html，将以下代码拷贝到文件中，选择浏览器打开即可。
注意：这里需要更改的是你的密钥和Title图片地址和名称，后文会讲到。
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<style type="text/css">
body, html{width: 100%;height: 100%;margin:0;font-family:"微软雅黑";}
#allmap{height:750px;width:100%;}
#r-result{width:100%; font-size:14px;}
</style>
<script type="text/javascript" src="http://api.map.baidu.com/api?v=2.0&ak=您的密钥"></script>
<script type="text/javascript" src="http://api.map.baidu.com/library/Heatmap/2.0/src/Heatmap_min.js"></script>
<title>城市名定位</title>
</head>
<body>
<div id="allmap"></div>
<div id="r-result">
城市名: <input id="cityName" type="text" style="width:100px; margin-right:10px;" />
<input type="button" value="查询" onclick="theLocation()" />
<input type="button" onclick="openHeatmap();" value="显示热力图"/><input type="button" onclick="closeHeatmap();" value="关闭热力图"/>
</div>
</body>
</html>
<script type="text/javascript">
// 百度地图API功能
var map = new BMap.Map("allmap");
var point = new BMap.Point(116.418261, 39.921984);
map.centerAndZoom(point,15);
function theLocation(){
var city = document.getElementById("cityName").value;
if(city != ""){
map.centerAndZoom(city,15); // 用城市名设置地图中心点
}
}
//设置地图样式
var mapStyle={style : "dark" }
map.setMapStyle(mapStyle);
//在地图上添加图片文字等信息(版权控件)
var cr=new BMap.CopyrightControl({anchor:BMAP_ANCHOR_TOP_LEFT,offset:new BMap.Size(0,0)});
map.addControl(cr);
cr.addCopyright({id:1,content:"<img src='./5.bmp' style='width:1600px;' />"}); //需要更改为你的图片地址和名称
// 初始化地图， 设置中心点坐标和地图级别
//map.centerAndZoom(new BMap.Point(116.4035,39.915),15);
//setTimeout(function(){
// map.setZoom(14);
//}, 2000); //2秒后放大到14级
map.enableScrollWheelZoom(true);
var points =[
{"lng":116.418261,"lat":39.921984,"count":50},
{"lng":116.423332,"lat":39.916532,"count":51},
{"lng":116.419787,"lat":39.930658,"count":15},
{"lng":116.418455,"lat":39.920921,"count":40},
{"lng":116.418843,"lat":39.915516,"count":100},
{"lng":116.42546,"lat":39.918503,"count":6},
{"lng":116.423289,"lat":39.919989,"count":18},
{"lng":116.418162,"lat":39.915051,"count":80},
{"lng":116.422039,"lat":39.91782,"count":11},
{"lng":116.41387,"lat":39.917253,"count":7},
{"lng":116.41773,"lat":39.919426,"count":42},
{"lng":116.421107,"lat":39.916445,"count":4},
{"lng":116.417521,"lat":39.917943,"count":27},
{"lng":116.419812,"lat":39.920836,"count":23},
{"lng":116.420682,"lat":39.91463,"count":60},
{"lng":116.415424,"lat":39.924675,"count":8},
{"lng":116.419242,"lat":39.914509,"count":15},
{"lng":116.422766,"lat":39.921408,"count":25},
{"lng":116.421674,"lat":39.924396,"count":21},
{"lng":116.427268,"lat":39.92267,"count":1},
{"lng":116.417721,"lat":39.920034,"count":51},
{"lng":116.412456,"lat":39.92667,"count":7},
{"lng":116.420432,"lat":39.919114,"count":11},
{"lng":116.425013,"lat":39.921611,"count":35},
{"lng":116.418733,"lat":39.931037,"count":22},
{"lng":116.419336,"lat":39.931134,"count":4},
{"lng":116.413557,"lat":39.923254,"count":5},
{"lng":116.418367,"lat":39.92943,"count":3},
{"lng":116.424312,"lat":39.919621,"count":100},
{"lng":116.423874,"lat":39.919447,"count":87},
{"lng":116.424225,"lat":39.923091,"count":32},
{"lng":116.417801,"lat":39.921854,"count":44},
{"lng":116.417129,"lat":39.928227,"count":21},
{"lng":116.426426,"lat":39.922286,"count":80},
{"lng":116.421597,"lat":39.91948,"count":32},
{"lng":116.423895,"lat":39.920787,"count":26},
{"lng":116.423563,"lat":39.921197,"count":17},
{"lng":116.417982,"lat":39.922547,"count":17},
{"lng":116.426126,"lat":39.921938,"count":25},
{"lng":116.42326,"lat":39.915782,"count":100},
{"lng":116.419239,"lat":39.916759,"count":39},
{"lng":116.417185,"lat":39.929123,"count":11},
{"lng":116.417237,"lat":39.927518,"count":9},
{"lng":116.417784,"lat":39.915754,"count":47},
{"lng":116.420193,"lat":39.917061,"count":52},
{"lng":116.422735,"lat":39.915619,"count":100},
{"lng":116.418495,"lat":39.915958,"count":46},
{"lng":116.416292,"lat":39.931166,"count":9},
{"lng":116.419916,"lat":39.924055,"count":8},
{"lng":116.42189,"lat":39.921308,"count":11},
{"lng":116.413765,"lat":39.929376,"count":3},
{"lng":116.418232,"lat":39.920348,"count":50},
{"lng":116.417554,"lat":39.930511,"count":15},
{"lng":116.418568,"lat":39.918161,"count":23},
{"lng":116.413461,"lat":39.926306,"count":3},
{"lng":116.42232,"lat":39.92161,"count":13},
{"lng":116.4174,"lat":39.928616,"count":6},
{"lng":116.424679,"lat":39.915499,"count":21},
{"lng":116.42171,"lat":39.915738,"count":29},
{"lng":116.417836,"lat":39.916998,"count":99},
{"lng":116.420755,"lat":39.928001,"count":10},
{"lng":116.414077,"lat":39.930655,"count":14},
{"lng":116.426092,"lat":39.922995,"count":16},
{"lng":116.41535,"lat":39.931054,"count":15},
{"lng":116.413022,"lat":39.921895,"count":13},
{"lng":116.415551,"lat":39.913373,"count":17},
{"lng":116.421191,"lat":39.926572,"count":1},
{"lng":116.419612,"lat":39.917119,"count":9},
{"lng":116.418237,"lat":39.921337,"count":54},
{"lng":116.423776,"lat":39.921919,"count":26},
{"lng":116.417694,"lat":39.92536,"count":17},
{"lng":116.415377,"lat":39.914137,"count":19},
{"lng":116.417434,"lat":39.914394,"count":43},
{"lng":116.42588,"lat":39.922622,"count":27},
{"lng":116.418345,"lat":39.919467,"count":8},
{"lng":116.426883,"lat":39.917171,"count":3},
{"lng":116.423877,"lat":39.916659,"count":34},
{"lng":116.415712,"lat":39.915613,"count":14},
{"lng":116.419869,"lat":39.931416,"count":12},
{"lng":116.416956,"lat":39.925377,"count":11},
{"lng":116.42066,"lat":39.925017,"count":38},
{"lng":116.416244,"lat":39.920215,"count":91},
{"lng":116.41929,"lat":39.915908,"count":54},
{"lng":116.422116,"lat":39.919658,"count":21},
{"lng":116.4183,"lat":39.925015,"count":15},
{"lng":116.421969,"lat":39.913527,"count":3},
{"lng":116.422936,"lat":39.921854,"count":24},
{"lng":116.41905,"lat":39.929217,"count":12},
{"lng":116.424579,"lat":39.914987,"count":57},
{"lng":116.42076,"lat":39.915251,"count":70},
{"lng":116.425867,"lat":39.918989,"count":8}];
if(!isSupportCanvas()){
alert('热力图目前只支持有canvas支持的浏览器,您所使用的浏览器不能使用热力图功能~')
}
//详细的参数,可以查看heatmap.js的文档 https://github.com/pa7/heatmap.js/blob/master/README.md
//参数说明如下:
/* visible 热力图是否显示,默认为true
* opacity 热力的透明度,1-100
* radius 势力图的每个点的半径大小
* gradient {JSON} 热力图的渐变区间 . gradient如下所示
* {
.2:'rgb(0, 255, 255)',
.5:'rgb(0, 110, 255)',
.8:'rgb(100, 0, 255)'
}
其中 key 表示插值的位置, 0~1.
value 为颜色值.
*/
heatmapOverlay = new BMapLib.HeatmapOverlay({"radius":20});
map.addOverlay(heatmapOverlay);
heatmapOverlay.setDataSet({data:points,max:100});
//是否显示热力图
function openHeatmap(){
heatmapOverlay.show();
}
function closeHeatmap(){
heatmapOverlay.hide();
}
closeHeatmap();
function setGradient(){
/*格式如下所示:
{
0:'rgb(102, 255, 0)',
.5:'rgb(255, 170, 0)',
1:'rgb(255, 0, 0)'
}*/
var gradient = {};
var colors = document.querySelectorAll("input[type='color']");
colors = [].slice.call(colors,0);
colors.forEach(function(ele){
gradient[ele.getAttribute("data-key")] = ele.value;
});
heatmapOverlay.setOptions({"gradient":gradient});
}
//判断浏览区是否支持canvas
function isSupportCanvas(){
var elem = document.createElement('canvas');
return !!(elem.getContext && elem.getContext('2d'));
}
</script>
简要步骤如下：
（1）如果想调用百度地图API，首先你需要得在官网注册一个帐号然后申请一个密钥，注册网址：http://lbsyun.baidu.com/，在打开网页的最下方可以申请密钥，如下图所示：
（2）如果你只是想在浏览器及本地测试，创建应用类型选择为：浏览器端，Referer白名单输入：*，如下图所示：
（3）提交完成后，就会得到一个密钥，这个很重要，在你调用百度地图API的时候需要输入这个，也就是需要将“你的密钥”替换为你申请得到的密钥，如下图所示：
（4）然后你可以在百度地图开放平台上面查询你想要的功能以及代码，提供了各个功能的相应代码，超级有用，你完全可以自己调用，代码开放平台地址为：http://developer.baidu.com/map/jsdemo.htm#a1_2
示意图界面如下：
（5）然后你可以将各个功能以及代码进行组合，实现你想要的功能，具体的很多细节不再赘述，毕竟我也是个新手。