openlayers加载天地图在线地图(矢量,注记,影像图,地形图)并切换底图

已被阅读 6340 次 | 文章分类:OpenLayers | 2022-02-02 16:01

记录openlauers加载天地图在线地图服务的方式，以及交互切换底图的代码

1 依赖库简单介绍

openlayers 是一个可以在网页上渲染地图数据的开源javascript sdk

小白GIS

天地图是咱国内公司研发的；也是一个地图数据渲染sdk；除此之外还提供了很多在线的地图服务供我们直接调用

2 全部代码

openlayers加载天地图在线服务和切换底图的所有代码

                                        
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8" />
    <link
      rel="stylesheet"
      href="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/en/v6.12.0/css/ol.css"
      type="text/css"
    />
    <style>
      html,
      body,
      .map {
        height: 100%;
        width: 100%;
        margin: 0;
        padding: 0;
      }
      .tool {
        position: absolute;
        bottom: 10px;
        right: 10px;

        margin: 0;
        padding: 0;
      }
      .tool-toggle {
        display: flex;
      }
      .tool-toggle__item {
        width: 100px;
        height: 100px;
        margin: 0 5px;
      }
      .tool-toggle__item > img {
        width: 100px;
        height: 100px;
        border-radius: 50%;
        border: solid 1px #2fb0f9;
      }
      .tool-toggle__item:hover img {
        cursor: pointer;
        transform: scale(1.1);
      }
    </style>
    <script src="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/en/v6.12.0/build/ol.js"></script>
    <title>GeoJson预览</title>
  </head>
  <body>
    <!-- 底图 -->
    <div id="map" class="map"></div>
    <!-- 工具 -->
    <div class="tool">
      <div class="tool-toggle" id="toggle">
        <div class="tool-toggle__item">
          <img src="http://lbs.tianditu.gov.cn/images/vec_c.png" name="vec" />
        </div>
        <div class="tool-toggle__item">
          <img src="http://lbs.tianditu.gov.cn/images/img_c.png" name="img" />
        </div>

        <div class="tool-toggle__item">
          <img src="http://lbs.tianditu.gov.cn/images/ter_c.png" name="ter" />
        </div>
      </div>
    </div>
    <script type="text/javascript">
      var map = new ol.Map({
        target: 'map',
        view: new ol.View({
          center: ol.proj.fromLonLat([119, 37]),
          zoom: 4,
        }),
      });
      let currentBaseMap = '';
      let basemaps = new Map();
      // 矢量图
      let vec_w = createVec_w();
      // 中文注记
      let cva_w = createCva_w();
      // 影像图
      let img_w = createImg_w();
      // 地形图
      let ter_w = createTer_w();

      map.addLayer(vec_w);
      map.addLayer(cva_w);
      currentBaseMap = 'vec_w';
      // 将图层全部用Map存储起来
      basemaps.set('vec_w', vec_w);
      basemaps.set('img_w', img_w);
      basemaps.set('ter_w', ter_w);

      // 底图切换事件
      var toggleDom = document.getElementById('toggle');
      toggleDom.onclick = function (evt) {
        var ev = ev || window.event;
        var target = ev.target || ev.srcElement;
        if (target.nodeName.toLocaleLowerCase() == 'img') {
          switch (target.name) {
            case 'vec':
              handleLayer('vec_w');
              break;
            case 'img':
              handleLayer('img_w');
              break;
            case 'ter':
              handleLayer('ter_w');
              break;
            default:
              break;
          }
        }
      };
      // 移除上个图层，添加要切换的图层
      function handleLayer(type) {
        if (currentBaseMap === type) {
          return;
        }
        map.removeLayer(basemaps.get(currentBaseMap));
        map.addLayer(basemaps.get(type));
        currentBaseMap = type;
      }
      // 创建矢量底图
      function createVec_w() {
        var source = new ol.source.XYZ({
          url: 'http://t4.tianditu.com/DataServer?T=vec_w&tk=81b9a9cf3e4be1df181e7bf54c5949fc&x={x}&y={y}&l={z}',
        });
        var layer = new ol.layer.Tile({
          id: 'tileLayer',
          title: '矢量底图',
          layerName: 'baseMap',
          source: source,
          zIndex: 0,
        });
        return layer;
      }
      // 创建标注图层
      function createCva_w() {
        var source = new ol.source.XYZ({
          url: 'http://t4.tianditu.com/DataServer?T=cva_w&tk=81b9a9cf3e4be1df181e7bf54c5949fc&x={x}&y={y}&l={z}',
        });
        var layer = new ol.layer.Tile({
          id: 'tileLayer',
          title: '标注图层',
          layerName: 'baseMap',
          source: source,
          zIndex: 1,
        });
        return layer;
      }
      // 创建影像底图
      function createImg_w() {
        var source = new ol.source.XYZ({
          url: 'http://t4.tianditu.com/DataServer?T=img_w&tk=81b9a9cf3e4be1df181e7bf54c5949fc&x={x}&y={y}&l={z}',
        });
        var layer = new ol.layer.Tile({
          id: 'tileLayer',
          title: '影像底图',
          layerName: 'baseMap',
          source: source,
          zIndex: 0,
        });
        return layer;
      }
      // 创建地形底图
      function createTer_w() {
        var source = new ol.source.XYZ({
          url: 'http://t4.tianditu.com/DataServer?T=ter_w&tk=81b9a9cf3e4be1df181e7bf54c5949fc&x={x}&y={y}&l={z}',
        });
        var layer = new ol.layer.Tile({
          id: 'tileLayer',
          title: '地形',
          layerName: 'baseMap',
          source: source,
          zIndex: 0,
        });
        return layer;
      }
    </script>
  </body>
</html>

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