Is it possible to get the latitude and longitude of a draggable marker in a map (using javascript) into a form in HTML?

问题

I am trying to obtain the Latitude and longitude of a draggable marker in google maps. I need this values to go directly into the value attribute in an <input type="text">. I've managed to do this, the only problem is that I don't know how to add a geocoder so the user can type their own address and get the lat and lng, but they also need to be albe to drag the marker in case google maps isn't accurate. I'll put my code down here. Appreciate if anyone could help.

HTML

<!DOCTYPE html> <html> <head> <meta charset=utf-8 /> <script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false"></script> </head> <body> <input type="text" id="latitude" placeholder="latitude"> <input type="text" id="longitude" placeholder="longitude"> <div id="map" style="width:500px; height:500px"></div> <p><input class="postcode" id="Postcode" name="Postcode" type="text"> <input type="submit" id="findbutton" value="Find" /></p> </body> </html>

JavaScript

        function initialize() {
        var $latitude = document.getElementById('latitude');
        var $longitude = document.getElementById('longitude');
        var latitude = 50.715591133433854
        var longitude = -3.53485107421875;
        var zoom = 16;
        var geocoder;

        var LatLng = new google.maps.LatLng(latitude, longitude);

        var mapOptions = {
            zoom: zoom,
            center: LatLng,
            panControl: false,
            zoomControl: false,
            scaleControl: true,
            mapTypeId: google.maps.MapTypeId.ROADMAP
        }   

        var map = new google.maps.Map(document.getElementById('map'),mapOptions);

        geocoder = new google.maps.Geocoder();  

        var marker = new google.maps.Marker({
            position: LatLng,
            map: map,
            title: 'Drag Me!',
            draggable: true
        });

        google.maps.event.addListener(marker, 'dragend', function(marker){
            var latLng = marker.latLng;
            $latitude.value = latLng.lat();
            $longitude.value = latLng.lng();
        });


    }
    $(document).ready(function () {

        initialize();

        $('#findbutton').click(function (e) {
            var address = $(PostCodeid).val();
            geocoder.geocode({ 'address': address }, function (results, status) {
                if (status == google.maps.GeocoderStatus.OK) {
                    map.setCenter(results[0].geometry.location);
                    marker.setPosition(results[0].geometry.location);
                    $(latitude).val(marker.getPosition().lat());
                    $(longitude).val(marker.getPosition().lng());
                } else {
                    alert("Geocode was not successful for the following reason: " + status);
                }
            });
            e.preventDefault();
        });
    });

回答1:

add the google.maps.Geocoder.
call it with the address provided, using the returned coordinates to place a marker on the map.
get the coordinates of that marker

working snippet:

var geocoder = new google.maps.Geocoder();
var marker = null;
var map = null;
function initialize() {
      var $latitude = document.getElementById('latitude');
      var $longitude = document.getElementById('longitude');
      var latitude = 50.715591133433854
      var longitude = -3.53485107421875;
      var zoom = 16;

      var LatLng = new google.maps.LatLng(latitude, longitude);

      var mapOptions = {
        zoom: zoom,
        center: LatLng,
        panControl: false,
        zoomControl: false,
        scaleControl: true,
        mapTypeId: google.maps.MapTypeId.ROADMAP
      }

      map = new google.maps.Map(document.getElementById('map'), mapOptions);
      if (marker && marker.getMap) marker.setMap(map);
      marker = new google.maps.Marker({
        position: LatLng,
        map: map,
        title: 'Drag Me!',
        draggable: true
      });

      google.maps.event.addListener(marker, 'dragend', function(marker) {
        var latLng = marker.latLng;
        $latitude.value = latLng.lat();
        $longitude.value = latLng.lng();
      });


    }
    initialize();
    $('#findbutton').click(function (e) {
        var address = $("#Postcode").val();
        geocoder.geocode({ 'address': address }, function (results, status) {
            if (status == google.maps.GeocoderStatus.OK) {
                map.setCenter(results[0].geometry.location);
                marker.setPosition(results[0].geometry.location);
                $(latitude).val(marker.getPosition().lat());
                $(longitude).val(marker.getPosition().lng());
            } else {
                alert("Geocode was not successful for the following reason: " + status);
            }
        });
        e.preventDefault();
    });

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false"></script>
    <input type="text" id="latitude" placeholder="latitude">
    <input type="text" id="longitude" placeholder="longitude">
    <div id="map" style="width:500px; height:500px"></div>
    <p><input class="postcode" id="Postcode" name="Postcode" type="text" value="New York, NY">
    <input type="submit" id="findbutton" value="Find" /></p>

来源：https://stackoverflow.com/questions/27156233/is-it-possible-to-get-the-latitude-and-longitude-of-a-draggable-marker-in-a-map

标签

google-maps

latitude-longitude

google-geocoder