Removing leaflet layers and L.marker method

问题:

I was wondering if anyone knows how or if you can actually remove a layer of points after adding them using this convention:

var pointsLayer, someFeatures = [{
            //Hard coded for now
            "type": "Feature",
            "properties": {
                "name": "Company A",
                "show_on_map": true,
                "icon": 'img/violations.png'
            },
            "geometry": {
                "type": "Point",
                "coordinates": [43.22519, -107.69348]
            }
        }, {
            "type": "Feature",
           .
           .
           .
   }];
for(w=0; w < someFeatures.length; w++){
                pointsLayer = L.marker(someFeatures[w].geometry.coordinates, {icon: violations})   
                    .bindPopup("Company: "+someFeatures[w].properties.name);
                    //add map points 
                    map.addLayer(pointsLayer);
            }

The typical removeLayer(pointsLayer); within a similar for loop does not work for me. But, that does not mean that there isn't a way to loop through. I am just not sure exactly how. I am trying to add points, which is working, and then remove them on an event (not working). Any ideas?

Thanks all.

P.S. Please don't forget to give the old thumbs up if you think this question was relevant or helpful, cheers.

回答1:

Instead of adding all markers directly on the map, you can add the markers on a separate layer (i.e. var markers = new L.FeatureGroup();) and then add that layer on the map (map.addLayer(markers);) outside the loop.

For example,

http://jsfiddle.net/9BXL7/

html

<button>remove all markers</button>
<div id="map"></div>

css

html, body, #map {
    width: 100%;
    height: 100%;
    padding: 0;
    margin: 0;
}

js

var cloudmade = L.tileLayer('http://{s}.tile.cloudmade.com/{key}/997/256/{z}/{x}/{y}.png', {
    maxZoom: 18,
    attribution: 'Map data © 2011 OpenStreetMap contributors, Imagery © 2011 CloudMade',
    key: 'BC9A493B41014CAABB98F0471D759707'
});

var map = L.map('map')
    .setView([50.5, 30.51], 15)
    .addLayer(cloudmade);

var markers = new L.FeatureGroup();

function getRandomLatLng(map) {
    var bounds = map.getBounds(),
        southWest = bounds.getSouthWest(),
        northEast = bounds.getNorthEast(),
        lngSpan = northEast.lng - southWest.lng,
        latSpan = northEast.lat - southWest.lat;

    return new L.LatLng(
    southWest.lat + latSpan * Math.random(),
    southWest.lng + lngSpan * Math.random());
}

function populate() {
    for (var i = 0; i < 10; i++) {
        var marker = L.marker(getRandomLatLng(map));
        marker.bindPopup("<p>Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Donec odio. Quisque volutpat mattis eros. Nullam malesuada erat ut turpis. Suspendisse urna nibh, viverra non, semper suscipit, posuere a, pede.</p><p>Donec nec justo eget felis facilisis fermentum. Aliquam porttitor mauris sit amet orci. Aenean dignissim pellentesque.</p>", {
            showOnMouseOver: true
        });
        markers.addLayer(marker);
    }
    return false;
}

map.addLayer(markers);

populate();
function removeAllMarkers(){
    map.removeLayer(markers);
}
document.querySelector('button').onclick=function(){removeAllMarkers()};

Should you need to DELETE or clear the markers layer to swap out the points in the future use:

markers.clearLayers();

回答2:

Use map.removeLayer():

var circle = L.circle([lat, lng], 1000).addTo(map);
map.removeLayer(circle);

回答3:

You can go over all layers directly in object 'map'.

for ( key in map['_layers'] ){
    if(typeof map['_layers'][key]['feature'] !== 'undefined') {
        var l = map['_layers'][key];
        if( l['feature']['properties']['name'] === 'Company A' ) l.removeFrom(map);}}