Google Maps Api 相当新。我有一组数据，我想循环浏览并在地图上绘制。看起来相当简单，但我发现的所有多标记教程都相当复杂。
让我们以 Google 网站上的数据数组为例：
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]
];
我只想绘制所有这些点，并infoWindow在单击以显示名称时弹出一个窗口。
这是我可以将其简化为的最简单的方法：
<!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?key=YOUR_API_KEY"
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>
截屏
将回调参数传递给addListener方法时，会发生一些闭包魔法。如果您不熟悉闭包的工作原理，这可能是一个非常棘手的话题。如果是这种情况，我建议查看以下 Mozilla 文章以获取简要介绍：
这是加载具有唯一性title和infoWindow文本的多个标记的另一个示例。使用最新的谷歌地图 API V3.11 测试。
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<title>Multiple Markers Google Maps</title>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.0/jquery.min.js"></script>
<script src="https://maps.googleapis.com/maps/api/js?v=3.11&sensor=false" type="text/javascript"></script>
<script type="text/javascript">
// check DOM Ready
$(document).ready(function() {
// execute
(function() {
// map options
var options = {
zoom: 5,
center: new google.maps.LatLng(39.909736, -98.522109), // centered US
mapTypeId: google.maps.MapTypeId.TERRAIN,
mapTypeControl: false
};
// init map
var map = new google.maps.Map(document.getElementById('map_canvas'), options);
// NY and CA sample Lat / Lng
var southWest = new google.maps.LatLng(40.744656, -74.005966);
var northEast = new google.maps.LatLng(34.052234, -118.243685);
var lngSpan = northEast.lng() - southWest.lng();
var latSpan = northEast.lat() - southWest.lat();
// set multiple marker
for (var i = 0; i < 250; i++) {
// init markers
var marker = new google.maps.Marker({
position: new google.maps.LatLng(southWest.lat() + latSpan * Math.random(), southWest.lng() + lngSpan * Math.random()),
map: map,
title: 'Click Me ' + i
});
// process multiple info windows
(function(marker, i) {
// add click event
google.maps.event.addListener(marker, 'click', function() {
infowindow = new google.maps.InfoWindow({
content: 'Hello, World!!'
});
infowindow.open(map, marker);
});
})(marker, i);
}
})();
});
</script>
</head>
<body>
<div id="map_canvas" style="width: 800px; height:500px;"></div>
</body>
</html>
250 个标记的屏幕截图：
它会自动随机化 Lat/Lng 以使其独一无二。如果您想测试 500、1000、xxx 标记和性能，此示例将非常有用。
我想我会把它放在这里，因为对于那些开始使用 Google Maps API 的人来说，它似乎是一个受欢迎的着陆点。在客户端呈现的多个标记可能是许多地图应用程序性能的下降。很难进行基准测试、修复，在某些情况下甚至确定存在问题（由于浏览器实现差异、客户端可用的硬件、移动设备，列表还在继续）。
开始解决此问题的最简单方法是使用标记聚类解决方案。基本思想是将地理上相似的位置分组为一个显示点数的组。当用户放大地图时，这些组会展开以显示下方的各个标记。
也许最简单的实现是markerclusterer库。基本实现如下（在库导入之后）：
<script type="text/javascript">
function initialize() {
var center = new google.maps.LatLng(37.4419, -122.1419);
var map = new google.maps.Map(document.getElementById('map'), {
zoom: 3,
center: center,
mapTypeId: google.maps.MapTypeId.ROADMAP
});
var markers = [];
for (var i = 0; i < 100; i++) {
var location = yourData.location[i];
var latLng = new google.maps.LatLng(location.latitude,
location.longitude);
var marker = new google.maps.Marker({
position: latLng
});
markers.push(marker);
}
var markerCluster = new MarkerClusterer({map, markers});
}
google.maps.event.addDomListener(window, 'load', initialize);
</script>
标记不是直接添加到地图中，而是添加到数组中。然后将此数组传递给为您处理复杂计算的库并附加到地图。
这些实现不仅极大地提高了客户端性能，而且在许多情况下还会导致更简单、更整洁的 UI，更容易消化更大规模的数据。
其他实现可从 Google 获得。
希望这有助于一些较新的人了解映射的细微差别。
异步版本：
<script type="text/javascript">
function initialize() {
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));
}
}
function loadScript() {
var script = document.createElement('script');
script.type = 'text/javascript';
script.src = 'https://maps.googleapis.com/maps/api/js?v=3.exp&' +
'callback=initialize';
document.body.appendChild(script);
}
window.onload = loadScript;
</script>
var arr = new Array();
function initialize() {
var i;
var Locations = [
{
lat:48.856614,
lon:2.3522219000000177,
address:'Paris',
gval:'25.5',
aType:'Non-Commodity',
title:'Paris',
descr:'Paris'
},
{
lat: 55.7512419,
lon: 37.6184217,
address:'Moscow',
gval:'11.5',
aType:'Non-Commodity',
title:'Moscow',
descr:'Moscow Airport'
},
{
lat:-9.481553000000002,
lon:147.190242,
address:'Port Moresby',
gval:'1',
aType:'Oil',
title:'Papua New Guinea',
descr:'Papua New Guinea 123123123'
},
{
lat:20.5200,
lon:77.7500,
address:'Indore',
gval:'1',
aType:'Oil',
title:'Indore, India',
descr:'Airport India'
}
];
var myOptions = {
zoom: 2,
center: new google.maps.LatLng(51.9000,8.4731),
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map"), myOptions);
var infowindow = new google.maps.InfoWindow({
content: ''
});
for (i = 0; i < Locations.length; i++) {
size=15;
var img=new google.maps.MarkerImage('marker.png',
new google.maps.Size(size, size),
new google.maps.Point(0,0),
new google.maps.Point(size/2, size/2)
);
var marker = new google.maps.Marker({
map: map,
title: Locations[i].title,
position: new google.maps.LatLng(Locations[i].lat, Locations[i].lon),
icon: img
});
bindInfoWindow(marker, map, infowindow, "<p>" + Locations[i].descr + "</p>",Locations[i].title);
}
}
function bindInfoWindow(marker, map, infowindow, html, Ltitle) {
google.maps.event.addListener(marker, 'mouseover', function() {
infowindow.setContent(html);
infowindow.open(map, marker);
});
google.maps.event.addListener(marker, 'mouseout', function() {
infowindow.close();
});
}
完整的工作示例。您只需复制、粘贴和使用即可。