Mapbox GL Js：添加和删除 GeoJSON 源和图层

Question

我在 mapbox gl 中添加和删除图层时遇到问题。

我有这一层：

   map.addLayer({
        "id": "route",
        "type": "line",
        "source": {
            "type": "geojson",
            "data": {
                "type": "Feature",
                "properties": {},
                "geometry": {
                    "type": "LineString",
                    "coordinates": [
                        [-122.48369693756104, 37.83381888486939],
                        [-122.48348236083984, 37.83317489144141],
                        [-122.48339653015138, 37.83270036637107],
                        [-122.48356819152832, 37.832056363179625],
                        [-122.48404026031496, 37.83114119107971],
                        [-122.48404026031496, 37.83049717427869],
                        [-122.48348236083984, 37.829920943955045],
                        [-122.48356819152832, 37.82954808664175],
                        [-122.48507022857666, 37.82944639795659],
                        [-122.48610019683838, 37.82880236636284],
                        [-122.48695850372314, 37.82931081282506],
                        [-122.48700141906738, 37.83080223556934],
                        [-122.48751640319824, 37.83168351665737],
                        [-122.48803138732912, 37.832158048267786],
                        [-122.48888969421387, 37.83297152392784],
                        [-122.48987674713133, 37.83263257682617],
                        [-122.49043464660643, 37.832937629287755],
                        [-122.49125003814696, 37.832429207817725],
                        [-122.49163627624512, 37.832564787218985],
                        [-122.49223709106445, 37.83337825839438],
                        [-122.49378204345702, 37.83368330777276]
                    ]
                }
            }
        },
        "layout": {
            "line-join": "round",
            "line-cap": "round"
        },
        "paint": {
            "line-color": "#888",
            "line-width": 8
        }
    });

然后我将其删除：

map.removeLayer('route')

一切正常。

然而，当我再次尝试添加同一层时，出现以下错误：

Error: There is already a source with this ID

尽管我正在添加一个图层。我不知道如何删除源，因为源没有 ID。

我的最终结果是能够通过单击按钮来添加和删除该图层。

有人可以帮我吗？

Answer 1

我刚刚发现源是使用与层中相同的 id 创建的，所以：

map.removeSource('route')

完美地完全删除图层和源。

Answer 2

您应该先删除图层，然后再删除其来源。

map.removeLayer(id);
map.removeSource(id);

你的情况 id = 'route'.

Answer 3

...并在尝试删除

之前检查 source/layer 是否存在

if (map.getLayer(id)) {
  map.removeLayer(id);
}
if (map.getSource(id)) {
  map.removeSource(id);
}

Mapbox GL Js：添加和删除 GeoJSON 源和图层

Mapbox GL Js: adding and removing GeoJSON sources and layers

mapbox-gl-js