传单:如果缩放级别大于9,则删除图层 [英] Leaflet : remove layer if zoom level greater than 9

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问题描述

我在Leaflet上建立了一个热图.
我的第一个目标是打开地图时查看热图.第二个目标是如果缩放级别大于9,则不查看热图.

I built a heatmap on Leaflet.
My first goal is to see the heatmap when you open the map. The second goal is not to view the heatmap if the zoom level is greater than 9.

我尝试过这个:

if (map.getZoom() >9 {
    map.removeLayer (heatmapLayer);     
};

但是它没有用.
您有什么建议吗?
谢谢!

But it did not work.
Would you have any suggestions ?
Thanks !

这是代码:

<!DOCTYPE html>
<html lang="en">
<head>
<title>Application - version 1.0</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="description" content="">
<meta name="author" content="">

<link rel="stylesheet" href="http://cdn.leafletjs.com/leaflet-0.6.3/leaflet.css" />
<link rel="stylesheet" href="style_p.css" />

<style type="text/css"> 
html, body, #map {
margin: 0;
margin-top: 0%;
width: 100%;
height: 100%;
};

</style>

</head>

<!-- Favicon -->
<link rel="icon" href="california.ico" />


<body>

<div id="map"></div>

<script src="http://cdn.leafletjs.com/leaflet-0.6.3/leaflet-src.js"></script>
<script src="http://maps.google.com/maps/api/js?v=3.2&sensor=false"></script>
<script src="jquery.js"></script>
<script type="text/javascript" src="heatmap.js"></script>
<script type="text/javascript" src="heatmap-leaflet.js"></script>
<script type="text/javascript" src="sloopjohnb.js"></script>
<script src="google.js"></script>
<script src="leaflet_search.js"></script>

<script type="text/javascript" charset="utf-8">  

$(function() {


var osm = new L.TileLayer('http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png');
var base = new L.TileLayer('http://129.206.74.245:8001/tms_r.ashx?x={x}&y={y}&z={z}');
var ggl2 = new L.Google('SATELLITE');

var heatmapLayer;
heatmapLayer = L.TileLayer.heatMap({
radius: 10,
opacity: 0.8,
gradient: {
0.45: "rgb(0,0,255)",
0.55: "rgb(0,255,255)",
0.65: "rgb(0,255,0)",
0.95: "yellow",
1.0: "rgb(255,0,0)"
}
});


var Data1={
max: 1,
data: sloopjohnb 
};
heatmapLayer.addData(Data1.data);

var baseMaps = {
"Fond OSM": osm,
"Fond de carte de base": base,
"Photo. aérienne Google" : ggl2

};

var overlayMaps = {
'Heatmap': heatmapLayer
};

map = new L.Map('map', {
minZoom : 1,
maxZoom : 11,
boxZoom : true,
layers: [base, heatmapLayer]
});

var controls = L.control.layers(baseMaps, overlayMaps, {position: 'bottomright'});
controls.addTo(map);

map.addControl(L.control.search());
L.control.scale().addTo(map);

map.attributionControl.addAttribution('<a href="http://www.patrick wied.at/static/heatmapjs/">Heatmap.js</a>');
map.setView(new L.LatLng(39.291,-5.9765),2);


// Disparition de la heatmap en fct du zoom
map.on('zoomend', function () {
if (map.getZoom() > 9) {
map.removeLayer(heatmapLayer);
}
}); 

});

</script>

</body>
</html>

推荐答案

确定要正确创建侦听器吗?

Are you sure you are creating the listener correctly?

例如,当用户缩放时,似乎应该调用它.就像这样:

已编辑

For example, this seems like it should be called when the user zooms. So something like:

Edited

map.on('zoomend', function () {
    if (map.getZoom() > 9 && map.hasLayer(heatmapLayer)) {
        map.removeLayer(heatmapLayer);
    }
    if (map.getZoom() < 9 && map.hasLayer(heatmapLayer) == false)
    {
        map.addLayer(heatmapLayer);
    }   
});


如果只希望基于缩放添加/删除图层,请不要在此处将其添加到图层控件中:


If you ONLY want the layer added/removed based on zoom, don't add it to your layer control here:

var controls = L.control.layers(baseMaps, overlayMaps, {position: 'bottomright'});

controls.addTo(map);
您只需要确保在必要时进行添加/删除即可.尝试弄乱此设置,看看会得到什么.另外,关于文档也写得很好. /reference.html#tilelayer"rel =" noreferrer> L.tileLayer

controls.addTo(map);
You will just have to make sure you are doing your adding/removing when it is necessary. Try messing with this set up a little and see where you get. Also, the Documentation is well written regarding the use of L.tileLayer

这篇关于传单:如果缩放级别大于9,则删除图层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!

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