有点用的Leaflet方法

一、判断某个点是否在矢量区域内。本身没有contains方法，只添加一个偷懒的方法。

L.Circle.include({
  contains: function (point) {
    let bounds = this.getBounds()
    return bounds.contains(point);
  },
});

L.Rectangle.include({
  contains: function (point) {
    let bounds = this.getBounds()
    return bounds.contains(point);
  },
});

L.Polygon.include({
  contains: function (point) {
    let bounds = this.getBounds()
    return bounds.contains(point);
  },
});

二、LayerGroup一次性添加多个点，写LayerGroup的话featureGroup中也会继承。

L.LayerGroup.include({
  addLayers: function (list) {
    for (let i = 0; i < list.length; i++) {
      let layer = list[i]
      // this.addLayer(layer)
      var id = this.getLayerId(layer);

  		this._layers[id] = layer;

  		if (this._map) {
  			this._map.addLayer(layer);
  		}
    }
  },
});