Question

我正在使用传单，正在查看GeoJSON，它的ID喜欢添加有关单击事件的多边形。

使用单张ive中的GeoJSON示例中的示例数据构建了以下内容，但我不知道该怎么做。

我确实使用了没有geojson的多边形图层，并且确实设法单击添加了一个图层，但是并没有删除它，而是反复添加了图层

感谢您的帮助

<html>
    <head>
            <link rel="stylesheet" href="https://unpkg.com/leaflet@1.6.0/dist/leaflet.css"
            integrity="sha512-xwE/Az9zrjBIphAcBb3F6JVqxf46+CDLwfLMHloNu6KEQCAWi6HcDUbeOfBIptF7tcCzusKFjFw2yuvEpDL9wQ=="
            crossorigin=""/>
    </head>
<body>
    <a href="javascript:add_layer('Republican')">Republican</a> | <a href="javascript:add_layer('Democrat')">Democrat</a>
 <div id="map" style="height:700px;"></div>
 <script src="https://unpkg.com/leaflet@1.6.0/dist/leaflet.js"
   integrity="sha512-gZwIG9x3wUXg2hdXF6+rVkLF/0Vi9U8D2Ntg4Ga5I5BZpVkVxlJWbSQtXPSiUTtC0TjtGOmxa1AJPuV0CPthew=="
   crossorigin=""></script>
<script type="text/javascript">
var map = L.map('map').setView([40, -97.], 5);
L.tileLayer('https://api.mapbox.com/styles/v1/{id}/tiles/{z}/{x}/{y}?access_token={accessToken}', {
    attribution: 'Map data &copy; <a href="https://www.openstreetmap.org/">OpenStreetMap</a> contributors, <a href="https://creativecommons.org/licenses/by-sa/2.0/">CC-BY-SA</a>, Imagery © <a href="https://www.mapbox.com/">Mapbox</a>',
    maxZoom: 18,
    id: 'mapbox/streets-v11',
    accessToken: 'x'
}).addTo(map);

var states = [{
    "type": "Feature",
    "properties": {"party": "Republican"},
    "geometry": {
        "type": "Polygon",
        "coordinates": [[
            [-104.05, 48.99],
            [-97.22,  48.98],
            [-96.58,  45.94],
            [-104.03, 45.94],
            [-104.05, 48.99]
        ]]
    }
}, {
    "type": "Feature",
    "properties": {"party": "Democrat"},
    "geometry": {
        "type": "Polygon",
        "coordinates": [[
            [-109.05, 41.00],
            [-102.06, 40.99],
            [-102.03, 36.99],
            [-109.04, 36.99],
            [-109.05, 41.00]
        ]]
    }
}];

L.geoJSON(states);

function add_layer(value){
    if map.contains.feature.properties.party.case(value) {
        map.layer.remove(feature.properties.party.case(value))
    } else {
        feature.properties.party.case(value.addTo(map))
    }
}

</script>
</body>
</html>

编辑：添加/删除的新函数，该函数返回“ TypeError：尝试分配给只读属性”。 map.hasLayer行

function add_layer(value){
    if(map.hasLayer(value)) {
        map.removeLayer(value);
    }else{
        map.addLayer(value);
    }
}

Answer 1

对于您的问题：

您可以使用map.addLayer(layer)或layer.addTo(map) / map.removeLayer(layer)或layer.removeFrom(map)从地图或图层组添加和删除图层。

但是我认为最适合您的是使用图层控制https://leafletjs.com/examples/layers-control/


var states = [{
    "type": "Feature",
    "properties": {"party": "Republican"},
    "geometry": {
        "type": "Polygon",
        "coordinates": [[
            [-104.05, 48.99],
            [-97.22,  48.98],
            [-96.58,  45.94],
            [-104.03, 45.94],
            [-104.05, 48.99]
        ]]
    }
}, {
    "type": "Feature",
    "properties": {"party": "Democrat"},
    "geometry": {
        "type": "Polygon",
        "coordinates": [[
            [-109.05, 41.00],
            [-102.06, 40.99],
            [-102.03, 36.99],
            [-109.04, 36.99],
            [-109.05, 41.00]
        ]]
    }
}];


var democrat = L.geoJSON(states, {
        filter: function(feature, layer) {
        return feature.properties.party === "Democrat";
    }
});

var republican = L.geoJSON(states, {
        filter: function(feature, layer) {
        return feature.properties.party === "Republican";
    }
});

var overlayLayers= {
  "Republican": republican,
  "Democrat": democrat
};

L.control.layers(null,overlayLayers).addTo(mymap);

如果您想使用外部控件（例如您的示例）：

function add_layer(value){
        map.removeLayer(republican);
        map.removeLayer(democrat);

    if(value === "Republican"){
        map.addLayer(republican);
    }else{
        map.addLayer(democrat);
    }
}

您还可以检查地图上是否包含以下图层：map.hasLayer(layer)

传单-稍后在按属性点击时添加删除GeoJSON多边形吗？

1 个答案: