Google maps 谷歌地图API地理代码-返回GPS坐标
我有这个密码:Google maps 谷歌地图API地理代码-返回GPS坐标,google-maps,geocode,Google Maps,Geocode,我有这个密码: var get_lat = function(address) { geocoder.geocode( { 'address': address}, function(results, status) { if (status == google.maps.GeocoderStatus.OK) { console.log('lat is: '+ results[0].geometry.location.lat());
var get_lat = function(address) {
geocoder.geocode( { 'address': address}, function(results, status) {
if (status == google.maps.GeocoderStatus.OK) {
console.log('lat is: '+ results[0].geometry.location.lat());
return results[0].geometry.location.lat();
}
});
}
var get_lng = function(address) {
geocoder.geocode( { 'address': address}, function(results, status) {
if (status == google.maps.GeocoderStatus.OK) {
console.log('lng is: '+ results[0].geometry.location.lng());
return results[0].geometry.location.lng();
}
});
}
在控制台中,它打印我需要的坐标,但返回值始终未定义:
我在谷歌地图的经典初始化中使用它,如下所示:
function createMarker(latlng) {
var marker = new google.maps.Marker({
position: latlng,
map: map,
});
}
function initialize() {
var myOptions = {
zoom: 8,
center: new google.maps.LatLng(49.210366,15.989588)
}
map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
var address = "Correct address that console.logs the correct GPS coordinations in function definitions above";
var gps_lat = get_lat(address);
var gps_lng = get_lng(address);
console.log('GPS lat: ' + gps_lat); // logs "undefined"
console.log('GPS lng: ' + gps_lng); // logs "undefined"
var marker = createMarker({lat: gps_lat}, lng: gps_lng});
}
$(window).on("load", function (e) {
initialize();
});
你知道为什么这个函数的值是正确的,但它不返回任何东西吗
对于GMAPAPI,我使用以下脚本:您在一个匿名函数中有一个返回,该函数传递给geocoder.geocode,所有这些都在另一个函数get\u lat/get\u lng中。get_lat/get_lng本身没有return语句,因此返回undefined
此外,geocoder.geocode将异步调用匿名函数。这意味着get_lat/get_lng没有机会获得返回值并将其返回到调用get_lat/get_lng的位置
最简单的一种解决方案是将createMarker代码放入geocoder.geocode的回调中。此外,在这种情况下,您必须合并两个get_lat/get_lng函数。例如:
geocoder.geocode( { 'address': address}, function(results, status) {
if (status == google.maps.GeocoderStatus.OK) {
var gps_lat = results[0].geometry.location.lat()
var gps_lng = results[0].geometry.location.lng();
console.log('lat is ' + gps_lat + '. lng is ' + gps_lng);
var marker = createMarker({lat: gps_lat, lng: gps_lng});
return results[0].geometry.location.lat();
}
});
您必须等到谷歌API给出响应。所以,编写一个逻辑,在GoogleAPI的回调函数中创建标记,如下所示
var getLatLng = function (address)
{
geocoder.geocode({ 'address': address }, function (results, status)
{
if (status == google.maps.GeocoderStatus.OK)
{
var location = results[0].geometry.location;
// Create marker once you get response from Google
createMarker({ lat: location.lat(), lng: location.lng() });
}
});
}
并调用该函数,如下所示
function initialize()
{
var myOptions =
{
zoom: 8,
center: new google.maps.LatLng(49.210366, 15.989588)
}
map = new google.maps.Map(document.getElementById("map"), myOptions);
var address = "Correct address that console.logs the correct GPS coordinations in function definitions above";
// Old code ------------------------------------------------
//var gps_lat = get_lat(address);
//var gps_lng = get_lng(address);
//console.log('GPS lat: ' + gps_lat); // logs "undefined"
//console.log('GPS lng: ' + gps_lng); // logs "undefined"
//var marker = createMarker({ lat: gps_lat, lng: gps_lng });
// ----------------------------------------------------------
// New code
getLatLng(address);
}
你会在地图上找到标记