如何从用户记忆中上传并在地图上显示 kml 文件

Question

我有一个代码可以显示地图并使用 openlayers 进行地理编码 library.You 还可以通过在地图上拖动来显示 kml 文件。现在我希望用户从设备内存中 select 这个文件并将其插入到地图中。例如，使用搜索按钮和 select 文件来执行此操作。 openlayers库可以用吗？我找不到 anything.How 我应该这样做吗？请指导我。谢谢这是我的代码：

<!DOCTYPE html>
<html>
  <head>
    <title>KML</title>
    <link rel="stylesheet" href="https://openlayers.org/en/v5.3.0/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/v4.6.5/build/ol.js"></script>
  </head>
  <body>
    <div id="map" class="map"></div>
    <div id="info">&nbsp;</div>
    <script>


      var raster = new ol.layer.Tile({
        source: new ol.source.BingMaps({
          imagerySet: 'Aerial',
          key: 'Ar3HbeAWJ2BNWw49Jnce_gbrbyqiPSBFuci9N4942gLNyBZgfzFPYn0d4QvpH06G'
        })
      });

      var vector = new ol.layer.Vector({
        source: new ol.source.Vector({
          url: 'Data/earth.kml',
          format: new ol.format.KML()
        })
      });

      var map = new ol.Map({
        layers: [raster, vector],
        target: document.getElementById('map'),
        view: new ol.View({
          center: [58.3005,37.0554],
          projection: 'EPSG:4326',
          zoom: 13
        })
      });

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

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

      map.on('click', function(evt) {
        displayFeatureInfo(evt.pixel);
      });
    </script>
  </body>
</html>

Answer 1

您可以使用 HTML 输入和 javascript FileReader

<div id="map" class="map"></div>
<input id="selectfile" type="file" accept=".kml" onchange="addKML()">
<div id="info">&nbsp;</div>
<script>

  function addKML() {

    var file = document.getElementById("selectfile").files[0];
    if (file) {

      var reader = new FileReader();
      reader.onload = function () {

        var vector = new ol.layer.Vector({
          source: new ol.source.Vector({
            url: reader.result,
            format: new ol.format.KML()
          })
        });
        map.addLayer(vector);

      }
      reader.readAsDataURL(file);

    }

  }

如何从用户记忆中上传并在地图上显示 kml 文件

How to upload and show kml file on map from user memory

javascript

html

openlayers

kml