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拖拽 Image Vector

发布于 2022-11-30 23:36:02 字数 4406 浏览 0 评论 0 收藏 0

本示例演示使用拖拽交互完成 image vector 渲染。

本示例演示使用拖拽交互完成渲染ol/layer/VectorImage图层。拖拽 GPX, GeoJSON, IGC, KML, or TopoJSON files 添加到地图上。每个文件在客户端渲染为一张图片。

main.js

import 'ol/ol.css';
import Map from 'ol/Map';
import View from 'ol/View';
import {
  DragAndDrop,
  defaults as defaultInteractions,
} from 'ol/interaction';
import {GPX, GeoJSON, IGC, KML, TopoJSON} from 'ol/format';
import {
  Tile as TileLayer,
  VectorImage as VectorImageLayer,
} from 'ol/layer';
import {Vector as VectorSource, XYZ} from 'ol/source';

const dragAndDropInteraction = new DragAndDrop({
  formatConstructors: [GPX, GeoJSON, IGC, KML, TopoJSON],
});

const key = 'Get your own API key at https://www.maptiler.com/cloud/';
const attributions =
  '<a href="https://www.maptiler.com/copyright/" target="_blank">&copy; MapTiler</a> ' +
  '<a href="https://www.openstreetmap.org/copyright" target="_blank">&copy; OpenStreetMap contributors</a>';

const map = new Map({
  interactions: defaultInteractions().extend([dragAndDropInteraction]),
  layers: [
    new TileLayer({
      source: new XYZ({
        attributions: attributions,
        url:
          'https://api.maptiler.com/tiles/satellite/{z}/{x}/{y}.jpg?key=' + key,
        maxZoom: 20,
      }),
    }),
  ],
  target: 'map',
  view: new View({
    center: [0, 0],
    zoom: 2,
  }),
});

dragAndDropInteraction.on('addfeatures', function (event) {
  const vectorSource = new VectorSource({
    features: event.features,
  });
  map.addLayer(
    new VectorImageLayer({
      source: vectorSource,
    })
  );
  map.getView().fit(vectorSource.getExtent());
});

const displayFeatureInfo = function (pixel) {
  const features = [];
  map.forEachFeatureAtPixel(pixel, function (feature) {
    features.push(feature);
  });
  if (features.length > 0) {
    const info = [];
    let i, ii;
    for (i = 0, ii = features.length; i < ii; ++i) {
      info.push(features[i].get('name'));
    }
    document.getElementById('info').innerHTML = info.join(', ') || '&nbsp';
  } else {
    document.getElementById('info').innerHTML = '&nbsp;';
  }
};

map.on('pointermove', function (evt) {
  if (evt.dragging) {
    return;
  }
  const pixel = map.getEventPixel(evt.originalEvent);
  displayFeatureInfo(pixel);
});

map.on('click', function (evt) {
  displayFeatureInfo(evt.pixel);
});

index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Drag-and-Drop Image Vector</title>
    <!-- Pointer events polyfill for old browsers, see https://caniuse.com/#feat=pointer -->
    <script src="https://unpkg.com/elm-pep"></script>
    <!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
    <script src="./resources/polyfill.min.js?features=fetch,requestAnimationFrame,Element.prototype.classList,URL,TextDecoder,Number.isInteger"></script>
    <style>
      .map {
        width: 100%;
        height:400px;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <div id="info">&nbsp;</div>
    <script src="main.js"></script>
  </body>
</html>

package.json

{
  "name": "drag-and-drop-image-vector",
  "dependencies": {
    "ol": "7.1.0"
  },
  "devDependencies": {
    "parcel": "^2.0.0-beta.1"
  },
  "scripts": {
    "start": "parcel index.html",
    "build": "parcel build --public-url . index.html"
  }
}

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