「AntV」L7 快速入门示例

1. 引言

L7 地理空间数据可视分析引擎是一种基于 WebGL 技术的地理空间数据可视化引擎，可以用于实现各种地理空间数据可视化应用。L7 引擎支持多种数据源和数据格式，包括 GeoJSON、CSV等，可以快速加载和渲染大规模地理空间数据。L7 引擎还提供了丰富的可视化效果和交互功能，包括热力图、等高线图、鼠标交互等，可以帮助用户更好地理解和分析地理空间数据。

L7 官网：蚂蚁地理空间数据可视化 | AntV (antgroup.com)

L7 GitHub 仓库：antvis/L7: 🌎 Large-scale WebGL-powered Geospatial Data Visualization analysis engine (github.com)

L7 官方教程：简介 | L7 (antgroup.com)

L7 官方示例：所有图表 | L7 (antgroup.com)

L7 API文档：场景 Scene | L7 (antgroup.com)

2. 快速上手

L7的主要特点是使用WebGL绘制地图数据，此处主要描述的是基础功能使用

通过CDN的方式可以快速引入L7：

<script src = 'https://unpkg.com/@antv/l7'></script>

通过NPM的方式引入L7可参考：

npm install @antv/l7

2.1 加载地图

加载地图：

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src='https://unpkg.com/@antv/l7'></script>
</head>

<body>
  <div id="map"></div>
  <script>
    const scene = new L7.Scene({
      id: 'map',
      map: new L7.GaodeMap({
        style: 'dark',
        center: [110.770672, 34.159869]
      }),
    });
  </script>
</body>

</html>

结果如下：

image-20230530160526639

L7内置了高德底图和Mapbox底图API，可以直接使用

2.2 加载底图

通常，使用栅格瓦片作为底图，L7 的栅格图层支持加载 TMS、WMS、WMTS 等多种格式的图片瓦片

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src='https://unpkg.com/@antv/l7'></script>
  <style>
    body,
    #map {
      height: 100vh;
      width: 100vw;
      margin: 0;
    }
  </style>
</head>

<body>
  <div id="map"></div>
  <script>
    const scene = new L7.Scene({
      id: 'map',
      map: new L7.Map({
        center: [110.770672, 34.159869],
        zoom: 4
      }),
    });

    const url1 =
      'https://t0.tianditu.gov.cn/img_w/wmts?tk=b72aa81ac2b3cae941d1eb213499e15e&';
    const layer1 = new L7.RasterLayer({
      zIndex: 1,
    }).source(url1, {
      parser: {
        type: 'rasterTile',
        tileSize: 256,
        wmtsOptions: {
          layer: 'img',
          tileMatrixset: 'w',
          format: 'tiles',
        },
      },
    });

    scene.on('loaded', () => {
      scene.addLayer(layer1);
    });
  </script>
</body>

</html>
  • 注意：L7目前只支持 3857 坐标系

结果如下：

image-20230530164635434

2.3 加载矢量数据

L7支持 GeoJSON数据

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src='https://unpkg.com/@antv/l7'></script>
  <style>
    body,
    #map {
      height: 100vh;
      width: 100vw;
      margin: 0;
    }
  </style>
</head>

<body>
  <div id="map"></div>
  <script>
    const scene = new L7.Scene({
      id: 'map',
      map: new L7.GaodeMap({
        center: [116.3956, 39.9392],
        zoom: 10,
        style: 'dark'
      })
    });
    scene.on('loaded', () => {
      fetch(
        'https://gw.alipayobjects.com/os/basement_prod/0d2f0113-f48b-4db9-8adc-a3937243d5a3.json'
      )
        .then(res => res.json())
        .then(data => {
          const layer = new L7.LineLayer({})
            .source(data)
          scene.addLayer(layer);
        });
    });
  </script>
</body>

</html>

结果如下：

image-20230530174539998

2.4 Marker标注

Marker标注是地图上用来标记信息的常用组件

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src='https://unpkg.com/@antv/l7'></script>
</head>

<body>
  <div id="map"></div>
  <script>
    const scene = new L7.Scene({
      id: 'map',
      map: new L7.GaodeMap({
        style: 'light',
        center: [110.770672, 34.159869]
      }),
    });

    const marker = new L7.Marker({
      color: '#f00'
    }).setLnglat([110.770672, 34.159869]);
    
    scene.addMarker(marker);
  </script>
</body>

</html>

结果如下：

image-20230530170134233

2.5 Popup弹窗

Popup弹窗是地图上用来显示信息的常用组件

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src='https://unpkg.com/@antv/l7'></script>
</head>

<body>
  <div id="map"></div>
  <script>
    const scene = new L7.Scene({
      id: 'map',
      map: new L7.GaodeMap({
        style: 'light',
        center: [110.770672, 34.159869]
      }),
    });

    const popup = new L7.Popup({
      title: '自定义标题',
      html: '<p>Popup 示例的自定义内容</p>',
      lngLat: {
        lng: 110.770672,
        lat: 34.159869,
      },
    });

    scene.addPopup(popup);
  </script>
</body>

</html>

结果如下：

image-20230530165325005

2.6 事件监听

L7支持事件鼠标点击、双击等事件监听

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src='https://unpkg.com/@antv/l7'></script>
</head>

<body>
  <div id="map"></div>
  <script>
    const scene = new L7.Scene({
      id: 'map',
      map: new L7.GaodeMap({
        style: 'light',
        center: [110.770672, 34.159869]
      }),
    });

    setTimeout(() => {
      scene.on('click', (e) => {
        console.log(e) // 鼠标左键点击事件
        const marker = new L7.Marker({
          color: '#f00'
        }).setLnglat([e.lnglat.lng, e.lnglat.lat]);
        scene.addMarker(marker);
      });
    }, 1000);
    // scene.on('click', (e) => {console.log(e)}); // 直接监听click事件会报错

  </script>
</body>

</html>

结果如下：

image-20230530173837195

2.7 地图控件

在使用地图时，常常需要使用缩放、比例尺等控件

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src='https://unpkg.com/@antv/l7'></script>
  <style>
    body,
    #map {
      height: 100vh;
      width: 100vw;
      margin: 0;
    }
  </style>
</head>

<body>
  <div id="map"></div>
  <script>
    const scene = new L7.Scene({
      id: 'map',
      map: new L7.GaodeMap({
        center: [116.3956, 39.9392],
        zoom: 10,
        style: 'light'
      })
    });
    
    scene.on('loaded', () => {
      const zoom = new L7.Zoom();
      scene.addControl(zoom);
      const scale = new L7.Scale();
      scene.addControl(scale);
    });

  </script>
</body>

</html>

结果如下：

image-20230530175039617

3. 参考资料

[1] 简介 | L7 (antgroup.com)

[2] 所有图表 | L7 (antgroup.com)

[3] 场景 Scene | L7 (antgroup.com)

posted @ 2023-05-30 18:01  当时明月在曾照彩云归  阅读(1155)  评论(4)  编辑  收藏  举报