Google maps api 3 图层未被删除-谷歌地图_Google Maps Api 3

Google maps api 3 图层未被删除-谷歌地图

google-maps-api-3

Google maps api 3 图层未被删除-谷歌地图,google-maps-api-3,Google Maps Api 3,我有谷歌地图： <!DOCTYPE html> <html> <head> <meta name="viewport" content="initial-scale=1.0, user-scalable=no"> <meta charset="utf-8"> <title>Fusion Tables layers</title> <style> html

我有谷歌地图：

<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no">
    <meta charset="utf-8">
    <title>Fusion Tables layers</title>
    <style>
      html, body {
        height: 100%;
        margin: 0;
        padding: 0;
      }
      #map {
        height: 100%;
      }
    </style>
  </head>
  <body>
    <div id="map"></div>
    <script>
      function initMap() {
        var map = new google.maps.Map(document.getElementById('map'), {
          zoom: 4,
          center: {lat: 39.8282, lng: -98.5795}
        });

        google.maps.event.addListener(map, 'zoom_changed', function() {
         var zoom_level = map.getZoom();
         var layer;
         var layer1;

         //state level
         if(zoom_level >= 5 && zoom_level < 7) {
           layer = new google.maps.FusionTablesLayer({
            query: {
              select: '\'geometry\'',
              from: '17aT9Ud-YnGiXdXEJUyycH2ocUqreOeKGbzCkUw'
            },
            styles: [{
              polygonOptions: {
                fillColor: '#000000',
                fillOpacity: 0.001
              }
            }]


          });
          layer.setMap(map);
          }

         //county level
         if(zoom_level >= 7) {
          layer = null;
          layer.setMap(null);
           layer1 = new google.maps.FusionTablesLayer({
            query: {
              select: '\'geometry\'',
              from: '1xdysxZ94uUFIit9eXmnw1fYc6VcQiXhceFd_CVKa'
            },
            styles: [{
              polygonOptions: {
                fillColor: '#000000',
                fillOpacity: 0.001
              }
            }]

          });
          layer1.setMap(map);
          }
        });
      }
    </script>
    <script async defer
    src="https://maps.googleapis.com/maps/api/js?key=AIzaSyBMtoh9P3UkoxbXndKu_HOP7KsVwTRvxGU&callback=initMap">
    </script>
  </body>
</html>

当我放大到zoomlevel 7及以上时，我仍然看到状态级别的图层，而不是图层1。放大时如何重置图层？

我建议，如果您一次只需要一个图层，请只创建一个，在创建新版本之前将其隐藏

google.maps.event.addListener(map, 'zoom_changed', function() {
  var zoom_level = map.getZoom();
  if (layer) layer.setMap(null);
  //state level
  if (zoom_level >= 5 && zoom_level < 7) {
    layer = new google.maps.FusionTablesLayer({
      query: {
        select: '\'geometry\'',
        from: '17aT9Ud-YnGiXdXEJUyycH2ocUqreOeKGbzCkUw'
      },
      styles: [{
        polygonOptions: {
          fillColor: '#000000',
          fillOpacity: 0.001
        }
      }]
    });
    layer.setMap(map);
  }
  //county level
  if (zoom_level >= 7) {
    layer = new google.maps.FusionTablesLayer({
      query: {
        select: '\'geometry\'',
        from: '1xdysxZ94uUFIit9eXmnw1fYc6VcQiXhceFd_CVKa'
      },
      styles: [{
        polygonOptions: {
          fillColor: '#000000',
          fillOpacity: 0.001
        }
      }]
    });
    layer.setMap(map);
  }
});