maptalks - Tilelayer强制重载

Tilelayer强制重载
index.html
<!DOCTYPE html>
<html>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>瓦片图层与地理投影 - Tilelayer强制重载</title>
  <style type="text/css">
    html,body{margin:0px;height:100%;width:100%}
    .container{width:100%;height:100%}
    .panel{border-radius:5px;padding:10px;position:absolute;z-index:1;right:10px;top:10px;border:1px solid gray;background-color:white}
    .panel .item{line-height:40px}
  </style>
  <link rel="stylesheet" href="https://unpkg.com/maptalks/dist/maptalks.css">
  <script type="text/javascript" src="https://unpkg.com/maptalks/dist/maptalks.min.js"></script>
  <body>
    <div class="panel">

        <div class="item">
            <button onclick="reload()">reload tilelayer</button>
        </div>


    </div>
    <div id="map" class="container"></div>

    <script>
      var map = new maptalks.Map('map', {
        center: [-100.43074996462228, 37.69212817202581],
        zoom: 4,
        spatialReference: {
          projection: 'EPSG:4326'
        },
        baseLayer: new maptalks.WMSTileLayer('wms', {
          'tileSystem': [1, -1, -180, 90],
          'urlTemplate': 'https://ows.terrestris.de/osm/service',
          'crs': 'EPSG:4326',
          'layers': 'OSM-WMS',
          'styles': '',
          'version': '1.3.0',
          'format': 'image/png',
          'transparent': true,
          'uppercase': true
        }),
        attribution: {
          content: '&copy ows.terrestris.de'
        }
      });

      var isTerrestris = true;
      function reload() {
        var baseLayer = map.getBaseLayer();
        var options = baseLayer.options;
        if (!isTerrestris) {
          options.urlTemplate = 'https://ows.terrestris.de/osm/service';
          options.layers = 'OSM-WMS';
        }
        else {
          options.urlTemplate = 'https://ahocevar.com/geoserver/wms';
          options.layers = 'topp:states';
        }
        baseLayer.forceReload();
        isTerrestris = !isTerrestris;

      }

    </script>
  </body>
</html>