原文链接及内容

运行界面

一个结合ol/layer/VectorImage图层使用拖放交互的示例(感觉和拖放那个例子唯一的不同就是底图数据不同🤔)。至于GPX、GeoJSON、IGC、KML、TopoJSON格式的文件可以使用拖放示例中的数据,这里没有投影转换支持,并且只适用于EPSG:4326EPSG:3857中的数据。

main.js代码如下:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
import Map from 'ol/Map.js';
import View from 'ol/View.js';
import {
DragAndDrop,
defaults as defaultInteractions,
} from 'ol/interaction.js';
import {GPX, GeoJSON, IGC, KML, TopoJSON} from 'ol/format.js';
import {
Tile as TileLayer,
VectorImage as VectorImageLayer,
} from 'ol/layer.js';
import {Vector as VectorSource, XYZ} from 'ol/source.js';

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);
});

界面布局文件index.html代码如下:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Drag-and-Drop</title>
<link rel="stylesheet" href="node_modules/ol/ol.css">
<style>
.map {
width: 100%;
height: 400px;
}
</style>
</head>
<body>
<div id="map" class="map"></div>
<div><label><input type="checkbox" id="extractstyles" checked /> Extract styles from KML</label></div>
<br />
<div>
<a id="download" download></a>
Download samples:&nbsp;&nbsp;
<button id="download-gpx">GPX</button>
&nbsp;
<button id="download-geojson">GeoJSON</button>
&nbsp;
<button id="download-igc">IGC</button>
&nbsp;
<button id="download-kml">KML</button>
&nbsp;
<button id="download-topojson">TopoJSON</button>
</div>
<br />
<div id="info">&nbsp;</div>
<!-- Pointer events polyfill for old browsers, see https://caniuse.com/#feat=pointer -->
<script src="https://cdn.jsdelivr.net/npm/elm-pep@1.0.6/dist/elm-pep.js"></script>
<script type="module" src="main.js"></script>
</body>
</html>