openlayers -框选 按住ctrl鼠标框选 

<!DOCTYPE html>
<html>
  <head>
    <title>Box Selection</title>
    <link rel="stylesheet" href="http://openlayers.org/en/v3.13.0/css/ol.css" type="text/css">
    <script src="http://openlayers.org/en/v3.13.0/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: '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
          })
        ],
        renderer: 'canvas',
        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 = '&nbsp;';
      });
      map.on('click', function() {
        selectedFeatures.clear();
        infoBox.innerHTML = '&nbsp;';
      });
    </script>
  </body>
</html>

 

posted @ 2022-06-17 11:16  devgis  阅读(371)  评论(0)  编辑  收藏  举报