基于Leaflet和高德Web API扩展地理编码服务
目录
需求背景:
需求很简单就是想调用高德地图的地理编码服务,单独扩展一个类出来。
参考地址:
Leaflet类扩展:https://leafletjs.com/examples/extending/extending-1-classes.html?tdsourcetag=s_pcqq_aiomsg
高德Web服务:https://lbs.amap.com/api/webservice/guide/api/georegeo
注意事项:
1.注意申请key;
2.Leaflet默认EPSG 3857坐标系,高德地图坐标系为GCJ-02,这俩其实一样。由于是调用高德的服务,如果地图为非3857坐标系,要注意坐标转换问题。
相关代码:
Geocoder.js:
L.GeoCoder = L.Class.extend({
initialize: function () {
this._geoUrl = 'https://restapi.amap.com/v3/geocode/geo?';
this._regeoUrl = 'https://restapi.amap.com/v3/geocode/regeo?';
this._address = " ";
this._location = " ";
},
/**
* 正向地理编码: 将地址描述信息转换成地理坐标(经纬度)
*/
getLocation: function (address,callback) {
let me = this;
var url = this._buildGeoUrl(address);
var request;
if (window.XMLHttpRequest) {
request = new XMLHttpRequest();
} else {
request = new ActiveXObject('Microsoft.XMLHTTP');
}
request.onreadystatechange = function () { // 状态发生变化时,函数被回调
if (request.readyState === 4) { // 成功完成
// 判断响应结果:
if (request.status === 200) {
// 成功,通过responseText拿到响应的文本:
return me._geoSuccess(request.responseText,callback);
} else {
// 失败,根据响应码判断失败原因:
return me._geoFail(request.status);
}
} else {
// HTTP请求还在继续...
}
}
// 发送请求:
request.open('GET', url);
request.send();
},
/**
* 逆向地理编码:将地理坐标(经纬度)转换成地址描述信息
*/
getAddress: function (location,callback) {
let me = this;
var url = this._buildRegeoUrl(location);
var request;
if(window.XMLHttpRequest){
request = new XMLHttpRequest();
} else {
request = new ActiveXObject('Microsoft.XMLHTTP');
}
request.onreadystatechange= function () {
if(request.readyState === 4){
if(request.status === 200){
return me._regeoSuccess(request.responseText,callback);
}else {
return me._regeoFail(request.status);
}
}else {
//
}
}
request.open('GET',url);
request.send();
},
/**
* 构建正向地理编码请求地址
* @private
*/
_buildGeoUrl: function (address) {
var url = this._geoUrl + 'address=' + address + '&key=yourkey';
return url;
},
/**
* 构建逆地理编码请求地址
* lnglat 经纬度坐标 格式:[110.235,38.31]
* @private
*/
_buildRegeoUrl: function (lnglat) {
var url = this._regeoUrl + 'location=' + lnglat[0] + ',' + lnglat[1] + '&key=yourkey';
return url;
},
/**
* 地理编码服务请求成功,回调方法
* @param response
* @private
*/
_geoSuccess: function (response,callback) {
return callback(response);
},
/**
* 地理编码服务请求失败
* @param response
* @private
*/
_geoFail: function (error) {
alert('请求失败'+ error);
},
/**
* 逆地理编码服务请求成功,回调方法
* @param response
* @private
*/
_regeoSuccess: function (response,callback) {
return callback(response);
},
_regeoFail: function (error) {
alert("请求失败"+ error);
}
});
L.geoCoder = function(){
return new L.GeoCoder();
}
example.html:
<script>
//注意坐标问题,该服务基于高德,坐标系为EPSG:3857,如果底图不是3857坐标系注意坐标转换
var map = L.map('map');
L.tileLayer('http://webrd0{s}.is.autonavi.com/appmaptile?lang=zh_cn&size=1&scale=1&style=8&x={x}&y={y}&z={z}',{maxZoom: 18,
minZoom: 4,subdomains:["1","2","3","4"]}).addTo(map);
map.setView(L.latLng(37.550339, 104.114129), 4);
document.getElementById("geo").onclick = geoCode;
function geoCode(){
var address = document.getElementById("address").value;
L.geoCoder().getLocation(address,function (res) {
console.log(res);
var json = JSON.parse(res);
var lnglat = json.geocodes[0].location; //格式为:经度,纬度
document.getElementById('lnglat').value = lnglat;
var temp = lnglat.split(',');
L.marker(L.latLng(temp[1],temp[0])).addTo(map);
});
}
</script>
原文件下载地址:https://download.csdn.net/download/wml00000/10843528
转载自:https://blog.csdn.net/wml00000/article/details/84957541