Get features under the mouse pointer | Mapbox GL JS

Use queryRenderedFeatures to show properties of hovered-over map elements.

JavaScript

React

JavaScript

React


<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Get features under the mouse pointer</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no">
<link href="https://api.mapbox.com/mapbox-gl-js/v3.9.0/mapbox-gl.css" rel="stylesheet">
<script src="https://api.mapbox.com/mapbox-gl-js/v3.9.0/mapbox-gl.js"></script>
<style>
body { margin: 0; padding: 0; }
#map { position: absolute; top: 0; bottom: 0; width: 100%; }
</style>
</head>
<body>
<style>
    #features {
        position: absolute;
        top: 0;
        right: 0;
        bottom: 0;
        width: 50%;
        overflow: auto;
        background: rgba(255, 255, 255, 0.8);
    }
    #map canvas {
        cursor: crosshair;
    }
</style>
<div id="map"></div>
<pre id="features"></pre>
<script>
	// TO MAKE THE MAP APPEAR YOU MUST
	// ADD YOUR ACCESS TOKEN FROM
	// https://account.mapbox.com
	mapboxgl.accessToken = 'YOUR_MAPBOX_ACCESS_TOKEN';
    const map = new mapboxgl.Map({
        container: 'map',
        // Choose from Mapbox's core styles, or make your own style with Mapbox Studio
        style: 'mapbox://styles/mapbox/streets-v12',
        center: [-96, 37.8],
        zoom: 3
    });

    map.on('mousemove', (e) => {
        const features = map.queryRenderedFeatures(e.point);

        // Limit the number of properties we're displaying for
        // legibility and performance
        const displayProperties = [
            'type',
            'properties',
            'id',
            'layer',
            'source',
            'sourceLayer',
            'state'
        ];

        const displayFeatures = features.map((feat) => {
            const displayFeat = {};
            displayProperties.forEach((prop) => {
                displayFeat[prop] = feat[prop];
            });
            return displayFeat;
        });

        // Write object as string with an indent of two spaces.
        document.getElementById('features').innerHTML = JSON.stringify(
            displayFeatures,
            null,
            2
        );
    });
</script>

</body>
</html>

このコードスニペットは、YOUR_MAPBOX_ACCESS_TOKENをあなたのMapboxアカウントのアクセストークンに置き換えるまで、期待通りに動作しません。

JavaScript

React


import React, { useEffect, useRef, useState } from 'react';
import mapboxgl from 'mapbox-gl';

import 'mapbox-gl/dist/mapbox-gl.css';

const MapboxExample = () => {
  const mapContainerRef = useRef();
  const mapRef = useRef();

  const [displayFeatures, setDisplayFeatures] = useState();

  useEffect(() => {
    // TO MAKE THE MAP APPEAR YOU MUST
    // ADD YOUR ACCESS TOKEN FROM
    // https://account.mapbox.com
    mapboxgl.accessToken = 'YOUR_MAPBOX_ACCESS_TOKEN';

    mapRef.current = new mapboxgl.Map({
      container: mapContainerRef.current,
      style: 'mapbox://styles/mapbox/streets-v12',
      center: [-96, 37.8],
      zoom: 3
    });

    mapRef.current.on('mousemove', (e) => {
      const features = mapRef.current.queryRenderedFeatures(e.point);

      const displayProperties = [
        'type',
        'properties',
        'id',
        'layer',
        'source',
        'sourceLayer',
        'state'
      ];

      const formattedFeatures = features.map((feat) => {
        const displayFeat = {};
        displayProperties.forEach((prop) => {
          displayFeat[prop] = feat[prop];
        });
        return displayFeat;
      });

      setDisplayFeatures(formattedFeatures);
    });
  }, []);

  return (
    <>
      <div
        id="map"
        ref={mapContainerRef}
        style={{ cursor: 'crosshair', height: '100%' }}
      ></div>
      <pre
        id="features"
        style={{
          position: 'absolute',
          top: 0,
          right: 0,
          bottom: 0,
          width: '50%',
          overflow: 'auto',
          background: 'rgba(255, 255, 255, 0.8)'
        }}
      >
        {JSON.stringify(displayFeatures, null, 2)}
      </pre>
    </>
  );
};

export default MapboxExample;

このコードスニペットは、YOUR_MAPBOX_ACCESS_TOKENをあなたのMapboxアカウントのアクセストークンに置き換えるまで、期待通りに動作しません。

追加の開発者リソース

このexampleは役に立ちましたか？