根据坐标获取详细地址方法 For 百度地图0+

24,576 views / 2012.05.07 / 5:05 下午

先看官方给出的文档，可以很简单的根据坐标获取详细地址：

<div style="width:200px;height:200px" id="container"></div>
 
<script>  var map = new BMap.Map("container"); map.centerAndZoom(new BMap.Point(116.404, 39.915), 11);
 
// 创建地理编码实例
 
function d(){
 
var myGeo = new BMap.Geocoder();
 
// 根据坐标得到地址描述
 
myGeo.getLocation(new BMap.Point(116.364, 39.993), function(result){    if (result){      alert(result.address);   }   }); }
 
</script>
 
<input type="button" onclick="d()" value="do" />

 

但是我们在做移动终端研发的时候，往往只能通过SDK获取到用户的坐标，如何才能让服务器获取用户的详细位置呢？（大众点评有实现）。我们运行上面的代码，抓包后分析发现，浏览器请求了这个地址：
http://api.map.baidu.com/?qt=rgc&x=12953722.17&y=4837205.83&dis_poi=100&poi_num=10&ie=utf-8&oue=1&res=api&callback=BMap._rd._cbk81902

看参数，这个x y 应该是坐标啊，可为什么跟我们传入的不一样呢？NND，原来百度给转换成了MC坐标，貌似这是搜过的算法啊！ 算了，在这个互相山寨的年代，也管不了这么多了。献出我的php算法：

<?php
function getRange($cF, $cE, $T) {  if ($cE != null) {   $cF = max($cF, $cE);  }  if ($T != null) {   $cF = min($cF, $T);  }  return $cF; } function getLoop($cF, $cE, $T) {  while ($cF > $T) {   $cF -= $T - $cE;  } while ($cF < $cE) {   $cF += $T - $cE;  }  return $cF; } function convertLL2MC($T) {  $LLBAND = array(75, 60, 45, 30, 15, 0);  $LL2MC = array(array(- 0.0015702102444, 111320.7020616939, 1704480524535203, -10338987376042340, 26112667856603880, -35149669176653700, 26595700718403920, -10725012454188240, 1800819912950474, 82.5), array(0.0008277824516172526, 111320.7020463578, 647795574.6671607, -4082003173.641316, 10774905663.51142, -15171875531.51559, 12053065338.62167, -5124939663.577472, 913311935.9512032, 67.5), array(0.00337398766765, 111320.7020202162, 4481351.045890365, -23393751.19931662, 79682215.47186455, -115964993.2797253, 97236711.15602145, -43661946.33752821, 8477230.501135234, 52.5), array(0.00220636496208, 111320.7020209128, 51751.86112841131, 3796837.749470245, 992013.7397791013, -1221952.21711287, 1340652.697009075, -620943.6990984312, 144416.9293806241, 37.5), array(- 0.0003441963504368392, 111320.7020576856, 278.2353980772752, 2485758.690035394, 6070.750963243378, 54821.18345352118, 9540.606633304236, -2710.55326746645, 1405.483844121726, 22.5), array(- 0.0003218135878613132, 111320.7020701615, 0.00369383431289, 823725.6402795718, 0.46104986909093, 2351.343141331292, 1.58060784298199, 8.77738589078284, 0.37238884252424, 7.45));  $T['lng'] = getLoop($T['lng'], -180, 180);  $T['lat'] = getRange($T['lat'], -74, 74);  for ($cF = 0; $cF < count($LLBAND); $cF++) {   if ($T['lat'] >= $LLBAND[$cF]) {    $cG = $LL2MC[$cF];    break;   }  }  if (!$cG) {   for ($cF = count($LLBAND) - 1; $cF >= 0; $cF--) {    if ($T['lng'] <= - $LLBAND[$cF]) {     $cG = $LL2MC[$cF];     break;    }   }  }  $cH = convertor($T, $cG);  $T = array(round($cH['lng'], 2), round($cH['lat'], 2));  return $T; } function convertor($cF, $cG) {  if (!$cF || !$cG) {   return false;  }  $T = $cG[0] + $cG[1] * abs($cF['lng']);  $cE = abs($cF['lat']) / $cG[9];  $cH = $cG[2] + $cG[3] * $cE + $cG[4] * $cE * $cE + $cG[5] * $cE * $cE * $cE + $cG[6] * $cE * $cE * $cE * $cE + $cG[7] * $cE * $cE * $cE * $cE * $cE + $cG[8] * $cE * $cE * $cE * $cE * $cE * $cE;  $T *= ($cF['lng'] < 0 ? -1: 1);  $cH *= ($cF['lat'] < 0 ? -1: 1);  return array("lng" => $T, "lat" => $cH); } $d = convertLL2MC(array("lng" => "116.364", "lat" => "39.993")); echo file_get_contents("<a href="http://api.map.baidu.com/?qt=rgc&x">http://api.map.baidu.com/?qt=rgc&x</a>=" . $d[0] . "&y=" . $d[1] . "&dis_poi=100&poi_num=10&ie=utf-8&oue=1&res=api&callback=");

?>

怎样，实现了吧？这事之所以这么麻烦，还是nodejs不够高级啊，不然直接架设个nodejs服务器，专门运行js脚本，我们就不用这么麻烦了。

杜工原创，转载注明来源，否则必究。

Categories: 感悟 Tags: ,