javascript - 谷歌地图 API 确定缩放级别?
问题描述
我们已经获得了以下代码,以在打开地图时显示特定的 Google Maps API 信息窗口:
https://jsfiddle.net/e26qyzxm/
问题是缩放级别在代码中被硬编码为:
map.setZoom(16);
如图所示,使用示例标记时效果很好。
但是,我们需要动态设置缩放级别,因此当从后端加载真实世界的标记时,缩放级别设置为略高于标记超出其集群的级别(如果有)。否则,16 的缩放级别可能太低,并且 infoWindow 可能不会显示,因为特定标记仍在群集中。
谁能建议修改代码来做到这一点?
HTML:
<div id="map"></div>
<!-- Replace the value of the key parameter with your own API key. -->
<script src="https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/markerclusterer.js"></script>
<script async defer
src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk&callback=initMap">
</script>
CSS:
#map {
height: 100%;
}
html, body {
height: 100%;
margin: 0;
padding: 0;
}
Javascript:
var MrkId = 62440;
var markersC = [];
var markersA = [];
var infowindow;
var map;
var markerCluster;
var points = [
['Point 1', 'adresse 1 ', 46.613317, 2.249830, 62437],
['Point 2', 'adresse 2 ', 46.713317, 2.249830, 62438],
['Point 3', 'adresse 3 ', 46.613317, 2.349830, 62439],
['Point 4', 'adresse 4 ', 46.713317, 2.449830, 62440],
['Point 5', 'adresse 5 ', 46.613317, 2.449830, 62441],
['Point 1', 'adresse 1 ', 46.413317, 2.249830, 62442],
['Point 2', 'adresse 2 ', 46.513317, 2.249830, 62443],
['Point 3', 'adresse 3 ', 46.513317, 2.349830, 62444],
['Point 4', 'adresse 4 ', 46.413317, 2.449830, 62445],
['Point 5', 'adresse 5 ', 46.513317, 2.449830, 62446],
];
function initMap() {
map = new google.maps.Map(document.getElementById('map'), {
center: {
lat: 46.613317,
lng: 2.349830
},
zoom: 9
});
infowindow = new google.maps.InfoWindow();
setMarkers();
}
function MkrClick(Mrk, Cnt, point) {
var contentString = '<div class="marker-infowindow">' + '<h2>' + point[0] + '</h1>' + '<div><a target="_blank" href="https://tutoandco.colas-delmas.fr/developpement/inserer-carte-google-maps-wordpress/?utm_source=jsfiddle&utm_medium=website">Voir le tuto complet</a></div></div>';
Mrk.addListener('click', function() {
infowindow.setContent(Cnt);
infowindow.open(map, Mrk);
});
}
function setMarkers() {
console.log("setMarkers")
for (var i = 0; i < points.length; i++) {
var point = points[i];
var contentString = '<div class="marker-infowindow">' + '<h2>' + point[0] + '</h1>' + '<div><a target="_blank" href="https://tutoandco.colas-delmas.fr/developpement/inserer-carte-google-maps-wordpress/?utm_source=jsfiddle&utm_medium=website">Voir le tuto complet</a></div></div>';
var marker = new google.maps.Marker({
position: {
lat: point[2],
lng: point[3]
},
map: map,
title: point[0],
loc_id: point[4],
loc_txt: contentString,
});
markersA.push(marker);
markersC.push(marker);
MkrClick(marker, contentString, point);
if (i == (points.length - 1)) {
// Add a marker clusterer to manage the markers.
markerCluster = new MarkerClusterer(map, markersC, {
imagePath: 'https://developers.google.com/maps/documentation/javascript/examples/markerclusterer/m'
});
if (MrkId != 0) {
ShowInfo(MrkId)
if (MrkId * 1 == point[4] * 1) {
console.log("MrkId=" + MrkId);
}
}
}
}
}
function ShowInfo(MrkIdSel) {
var IdxFound = -1;
for (var a = 0; a < markersC.length; a++) {
var McLoc = markersC[a].loc_id;
var McLocA = markersA[a].loc_id;
if (McLoc == MrkIdSel) {
IdxFound = a;
a = (markersC.length - 1)
}
if (a == (markersC.length - 1)) {
var bounds = new google.maps.LatLngBounds(markersC[IdxFound].position);
map.fitBounds(bounds);
setTimeout(function() {
map.setZoom(16);
google.maps.event.trigger(markersA[IdxFound], "click", {});
}, 125);
}
}
}
function isMarkerClustered(Marker) {
var clusters = markerCluster.clusters_;
var Pos = 0;
console.log("isMarkerClustered clusters.length=" + clusters.length)
for (var i = 0; i < clusters.length; i++) {
var Cmarkers = clusters[i].getMarkers();
for (var m = 0; m < Cmarkers.length; m++) {
if (Cmarkers[m] === Marker) {
Pos = clusters[i].getCenter()
}
if (i == (clusters.length - 1)) {
if (m == (Cmarkers.length - 1)) {
if (Pos != 0) {
Pos = Marker.position
}
var Info2 = new google.maps.InfoWindow({
//position: markersC[a].position,
position: Pos,
content: Marker.loc_txt,
}).open(map);
}
}
}
}
}
更新 1:
我想另一种方法是关闭集群并将缩放硬编码为 16。然后如果用户缩小,隐藏 infoWindow 并重新启用集群。如果有人可以建议修改代码来做到这一点,我将不胜感激。
解决方案
执行加载后,有了标记的位置,您可以使用bounds.extend
,map.fitBounds
因此地图会自动缩放以显示后端返回的所有引脚,如下所示:
//markers is an array that contains the loaded result
var bounds = new google.maps.LatLngBounds();
for (var i = 0, marker; marker = markers[i]; i++) {
//pass the location of each marker to bounds.extend
bounds.extend(marker.geometry.location);
}
//tell your map to sets the viewport to contain all the markers.
map.fitBounds(bounds);
如果您只想按邮政编码加载区域,例如,使用地理编码器,您还可以使用map.fitBounds
设置视口以显示地理编码器返回的整个特定区域,如下所示:
//response is the geocoder's response
map.fitBounds(response[0].geometry.viewport);
另一种解决方案可能是:
var geoCoder = new GClientGeocoder();
geoCoder.setViewport(map.getBounds());
geoCoder.getLocations('searchquery', function(latlng) {
if( latlng.Placemark.length > 0 ) {
var box = latlng.Placemark[0].ExtendedData.LatLonBox;
var bounds = new GLatLngBounds(new GLatLng(box.south, box.west), new GLatLng(box.north, box.east));
var center = new GLatLng(box.Placemark[0].Point.coordinates[1], latlng.Placemark[0].Point.coordinates[0]);
var zoom = oMap.getBoundsZoomLevel(bounds);
map.setCenter(center, zoom);
}
})
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