FeatureGroup

• setStyle applies path options to every vector child and silently ignores markers.
• getBounds merges child extents and can be handed straight to map.fitBounds.
• Child events bubble up with e.layer pointing at the clicked layer.

var group = L.featureGroup().addTo(map);

var buildings = [
  { bounds: [[39.902, 116.388], [39.906, 116.394]], name: 'A 区' },
  { bounds: [[39.906, 116.394], [39.911, 116.401]], name: 'B 区' }
];

buildings.forEach(function (b) {
  var rect = L.rectangle(b.bounds, { weight: 2, fillOpacity: 0.15 })
    .bindPopup(b.name);
  group.addLayer(rect);
});

/* 一次改所有面要素的样式 */
group.setStyle({ color: '#17694a', fillColor: '#22c55e' });

/* 子图层点击会冒泡到组，e.layer 是被点的那个 */
group.on('click', function (e) {
  var id = L.Util.stamp(e.layer);
  console.log('点击子图层', id);
});

map.fitBounds(group.getBounds(), { padding: [24, 24] });

• getBounds throws when a tile layer sits inside, because tile layers lack that method.
• Markers ignore setStyle, so restyling a mixed group only affects vector children.