Javascript 如何基于属性值过滤MapBox热图中的点？

假设我有一个基本的地图盒热图。生成此热图的矢量平铺的geojson如下所示：

{"type":"FeatureCollection",
    "features":[
         {"type":"Feature","properties":{"dbh":0, "icon-type": "bike"},"geometry":{"type":"Point","coordinates":[-79.91746,40.44356]}},
         {"type":"Feature","properties":{"dbh":12, "icon-type": "bike"},"geometry":{"type":"Point","coordinates":[-79.94606,40.44961]}},
         {"type":"Feature","properties":{"dbh":6, "icon-type": "cat"},"geometry":{"type":"Point","coordinates":[-79.96474,40.46283]}},
         {"type":"Feature","properties":{"dbh":2, "icon-type": "dog"},"geometry":{"type":"Point","coordinates":[-80.00949,40.42532]}}
     ]
}

我了解如何根据此处的教程显示热图：

请注意，geojson中的每个特性都有一个图标类型属性。我想动态地告诉我的热图只显示数据中具有特定图标类型值的点，例如“bike”或“cat”

---

如何实现这一点？

您可以在层配置中使用，如中所使用的

在您的情况下，它将类似于：

map.addLayer({
  id: 'heatmap-layer',
  type: 'heatmap',
  source: 'your-source',
  paint: { ... },
  filter: ['==', ['get', 'icon-type'], 'cat']
});

“==”

只允许下两个参数相等的功能

'get'

用于访问功能属性，因此

['get'，'icon type']

解析为功能的

图标类型

属性

“cat”是一个字符串literal