放大和缩小后计算地图上显示的标记 [英] count markers displayed on map after zoom in and out
问题描述
我正在使用google-maps-utility-library-v3. 我正在尝试放大和缩小，如果点不再出现在屏幕上，我想查看计数0. 但这是行不通的.如果我注释掉mgr.addMarkers(markers，5);它有效..但是它将始终为0，因为没有制造者由管理者管理. 有人可以告诉我为什么吗?
I am using google-maps-utility-library-v3. I am trying to zoom in and zoom out, if the dot is not in screen anymore, I want to see count 0. But it doesn't work. If I comment out mgr.addMarkers(markers,5); It works.... But it will always be 0 because no maker is managed by the manager. Could someone tell me why?
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<style type="text/css">
html { height: 100% }
body { height: 100%; margin: 0; padding: 0 }
#map_canvas { height: 100% }
</style>
<script type="text/javascript"
src="http://maps.googleapis.com/maps/api/js?key=??????????????&sensor=false">
</script>
<script type="text/javascript" src="downloadxml.js"></script>
<script src="http://google-maps-utility-library-v3.googlecode.com/svn/tags/markermanager/1.0/src/markermanager.js"></script>
<script type="text/javascript">
var map = null;
function initialize() {
var myOptions = {
zoom: 8,
center: new google.maps.LatLng(42.35428, -71.05525),
mapTypeId: google.maps.MapTypeId.ROADMAP
}
map = new google.maps.Map(document.getElementById('map'), myOptions);
//hard code a marker
var lat = 42.35428;
var lng = -71.05525;
var point = new google.maps.LatLng(lat,lng);
var html = "I am a hard-coded dot";
var marker = new google.maps.Marker({
map: map,
position: point,
icon: "http://www.google.com/mapfiles/arrow.png",
shadow: "http://www.google.com/mapfiles/arrowshadow.png"
});
var markers = [];
markers.push(marker);
var mgr = new MarkerManager(map);
mgr.addMarkers(markers,5);
mgr.refresh();
google.maps.event.addListener(map, 'zoom_changed', function() {
var zoomLevel = map.getZoom();
var count = mgr.getMarkerCount(zoomLevel);
document.getElementById("Listing").innerHTML += count + "<BR>";
});
}
</script>
推荐答案
在完全初始化之前，您似乎正在使用MarkerManager.这是代码的更新部分，可解决此问题:
You appear to be using the MarkerManager before it is fully initialized. Here's an updated section of your code to fix the issue:
var markers = [];
markers.push(marker);
var mgr = new MarkerManager(map);
google.maps.event.addListenerOnce(mgr, 'loaded', function(){
mgr.addMarkers(markers, 5);
mgr.refresh();
});
See this example as reference: http://google-maps-utility-library-v3.googlecode.com/svn/tags/markermanager/1.0/docs/examples.html
这篇关于放大和缩小后计算地图上显示的标记的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
