OpenLayers示例代码：选择框
OpenLayers示例代码：选择框
<!DOCTYPE html>
<html>
<head>
<title>Box Selection</title>
<link rel="stylesheet" href="https://openlayers.org/en/v4.0.1/css/ol.css" type="text/css">
<!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
<script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"></script>
<script src="https://openlayers.org/en/v4.0.1/build/ol.js"></script>
<style>
.ol-dragbox {
background-color: rgba(255,255,255,0.4);
border-color: rgba(100,150,0,1);
}
</style>
</head>
<body>
<div id="map" class="map"></div>
<div id="info">No countries selected</div>
<script>
var vectorSource = new ol.source.Vector({
url: 'https://openlayers.org/en/v4.0.1/examples/data/geojson/countries.geojson',
format: new ol.format.GeoJSON()
});
var map = new ol.Map({
layers: [
new ol.layer.Tile({
source: new ol.source.OSM()
}),
new ol.layer.Vector({
source: vectorSource
})
],
target: 'map',
view: new ol.View({
center: [0, 0],
zoom: 2
})
});
// a normal select interaction to handle click
var select = new ol.interaction.Select();
map.addInteraction(select);
var selectedFeatures = select.getFeatures();
// a DragBox interaction used to select features by drawing boxes
var dragBox = new ol.interaction.DragBox({
condition: ol.events.condition.platformModifierKeyOnly
});
map.addInteraction(dragBox);
var infoBox = document.getElementById('info');
dragBox.on('boxend', function() {
// features that intersect the box are added to the collection of
// selected features, and their names are displayed in the "info"
// div
var info = [];
var extent = dragBox.getGeometry().getExtent();
vectorSource.forEachFeatureIntersectingExtent(extent, function(feature) {
selectedFeatures.push(feature);
info.push(feature.get('name'));
});
if (info.length > 0) {
infoBox.innerHTML = info.join(', ');
}
});
// clear selection when drawing a new box and when clicking on the map
dragBox.on('boxstart', function() {
selectedFeatures.clear();
infoBox.innerHTML = ' ';
});
map.on('click', function() {
selectedFeatures.clear();
infoBox.innerHTML = ' ';
});
</script>
</body>
</html>
说明：
OpenLayers示例代码：选择框
