Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
236 views
in Technique[技术] by (71.8m points)

Find center of multiple locations in Google Maps

I have just copied the code on this question and applied my latitude and longitudes. However, the latitudes and longitudes will be dynamic, and the center of the map will change depending on the latitudes and longitudes of the locations.

The following is the code from the other question

<!DOCTYPE html>
<html>

    <head>
        <meta http-equiv="content-type" content="text/html; charset=UTF-8" />
        <title>Google Maps Multiple Markers</title>
        <script src="http://maps.google.com/maps/api/js?sensor=false" type="text/javascript"></script>
    </head>

    <body>
        <div id="map" style="width: 500px; height: 400px;"></div>
        <script type="text/javascript">
            var locations = [
                ['Bondi Beach', -33.890542, 151.274856, 4],
                ['Coogee Beach', -33.923036, 151.259052, 5],
                ['Cronulla Beach', -34.028249, 151.157507, 3],
                ['Manly Beach', -33.80010128657071, 151.28747820854187, 2],
                ['Maroubra Beach', -33.950198, 151.259302, 1]
            ];

            var map = new google.maps.Map(document.getElementById('map'), {
                zoom: 10,
                center: new google.maps.LatLng(-33.92, 151.25),
                mapTypeId: google.maps.MapTypeId.ROADMAP
            });

            var infowindow = new google.maps.InfoWindow();

            var marker, i;

            for (i = 0; i < locations.length; i++) {
                marker = new google.maps.Marker({
                    position: new google.maps.LatLng(locations[i][1], locations[i][2]),
                    map: map
                });

                google.maps.event.addListener(marker, 'click', (function(marker, i) {
                    return function() {
                        infowindow.setContent(locations[i][0]);
                        infowindow.open(map, marker);
                    }
                })(marker, i));
            }
        </script>
    </body>

</html>

So my question is, how could I know the center of the map when having dynamic locations. I've tried leaving the center blank but the map didn't load.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

First you can create a LatLngBounds object by including all the dynamically generated locations. Use the extend method to include the points. Then you can get the center of the bound using the getCenter method.

UPDATE:

Code:

var bound = new google.maps.LatLngBounds();

for (i = 0; i < locations.length; i++) {
  bound.extend( new google.maps.LatLng(locations[i][2], locations[i][3]) );

  // OTHER CODE
}

console.log( bound.getCenter() );

Illustration:

enter image description here


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...