---
title: "框选图层"
language: "en"
canonical: "https://l7.antv.antgroup.com/en/examples/tutorial/layer/layer-boxselect/"
---

# 框选图层

[Live example](https://l7.antv.antgroup.com/en/examples/tutorial/layer/layer-boxselect/)

[Resource index](/llms.txt)

Provide a DOM element with `id="container"`. The original example source follows.

## Source

```js
import { LineLayer, PolygonLayer, Scene } from '@antv/l7';
import { GaodeMap } from '@antv/l7-maps';

const scene = new Scene({
  id: 'map',
  map: new GaodeMap({
    style: 'light',
    center: [120.13618469238281, 30.247352897833554],
    zoom: 9,
  }),
});
scene.on('loaded', () => {
  fetch('https://mdn.alipayobjects.com/afts/file/A*nNheQL3Z-FUAAAAAAAAAAAAADrd2AQ/330100_full.json')
    .then((res) => res.json())
    .then((data) => {
      const fillLayer = new PolygonLayer({
        name: 'fill',
        autoFit: true,
      })
        .source(data)
        .shape('fill')
        .color('adcode', ['#f0f9e8', '#ccebc5', '#a8ddb5', '#7bccc4', '#43a2ca', '#0868ac']);

      const lineLayer = new LineLayer({
        zIndex: 1,
        name: 'line',
      })
        .source(data)
        .shape('line')
        .size(1)
        .color('#fff');

      const selectLayer = new LineLayer({
        zIndex: 2,
        name: 'select',
      })
        .source([])
        .shape('line')
        .size(2)
        .color('#f00');

      scene.addLayer(fillLayer);
      scene.addLayer(lineLayer);
      scene.addLayer(selectLayer);

      scene.enableBoxSelect(false);

      const onBoxSelect = (bbox, startEvent, endEvent) => {
        const { x: x1, y: y1 } = startEvent;
        const { x: x2, y: y2 } = endEvent;
        fillLayer.boxSelect(
          [Math.min(x1, x2), Math.min(y1, y2), Math.max(x1, x2), Math.max(y1, y2)],
          (features) => {
            selectLayer.setData({
              type: 'FeatureCollection',
              features: features ?? [],
            });
          },
        );
      };

      scene.on('selecting', onBoxSelect);
      scene.on('selectend', onBoxSelect);
    });
});
```

## Runtime environment

Before evaluating the example, await this setup in a page containing #container. Supporting files follow below.

```js
await (await import("/src/demo/setup.ts")).default({ container: document.getElementById('container'), path: "/examples/tutorial/layer/demo/layer-boxselect.js" });
```


## src/demo/setup.ts

```ts
import type { DemoSetupContext } from '@antv/astro-theme-antv';
import * as District from 'district-data';
import { GLTFLoader } from 'three/examples/jsm/loaders/GLTFLoader.js';

export default async function setup({ container, path }: DemoSetupContext) {
  // Tool pages provide their own React layout and SDK imports.
  if (!path.startsWith('/examples/')) return;
  // Retain only the original globals still used by gallery examples.
  Object.assign(window, { District, GLTFLoader });
  const map = document.createElement('div');
  map.id = 'map';
  container.append(map);
  await import('./map.css');
  // Match the original gallery's shared AMap environment, including raw AMap demos.
  await import('./amap');
}
```

## src/demo/map.css

```css
#map {
  position: relative;
  width: 100%;
  height: 100%;
  min-height: 320px;
}

.labelclass {
  position: absolute;
  display: inline;
  cursor: pointer;
  background: rgb(255, 228, 120);
  border: solid 2px #fff;
  padding: 4px;
  white-space: nowrap;
  font:
    bold 12px/18px arial,
    sans-serif;
  color: #fff;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  line-height: 30px;
  /* opacity: 0.7; */
  text-align: center;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  user-select: none;
}
```

## src/demo/amap.ts

```ts
import AMapLoader from '@amap/amap-jsapi-loader';

// Preserve the site's development and production SDK registrations.
const credentials = import.meta.env.DEV
  ? { key: '6f025e700cbacbb0bb866712d20bb35c', securityJsCode: '290ddc4b0d33be7bc9b354bc6a4ca614' }
  : { key: 'f59bcf249433f8b05caaee19f349b3d7', securityJsCode: '2653011adeb04230b3a26cc9a780a800' };
window._AMapSecurityConfig = { securityJsCode: credentials.securityJsCode };
await AMapLoader.load({ key: credentials.key, version: '2.0', plugins: ['Map3D'] });
```