Leaflet 数据可视化实现地图下钻示例详解

const getGeoJson = (code) => {
  return new Promise((resolve, inject) => {
    // /geojson代理
    axios.get(`/geojson/areas_v3/bound/geojson?code=$[code]`).then((res) => {
      if (res.data.features){
        resolve(res.data.features);
      } else {
        inject(res);
      }
    });
  });
}

function useLeaflet(idName){
    // options 参数 
    const initMap = (options) => {
    // 实例
    map.value = L.map(idName, options);  
    // @ts-ignore
    // 记载瓦片
    L.tileLayer?.chinaProvider('Geoq.Normal.PurplishBlue').addTo(map.value);
    map.value.setView([41.02999636902566, 108.984375], 3); 
  }
}

function useLeaflet(idName){
    // options 参数 
    const initMap = (options) => {
    // 实例
    map.value = L.map(idName, options);  
    // @ts-ignore
    // 记载瓦片
    L.tileLayer?.chinaProvider('Geoq.Normal.PurplishBlue').addTo(map.value);
    map.value.setView([41.02999636902566, 108.984375], 3); 
  }
  const updateGeoJson = (json) => {
    if (isArray(json) && json.length < 1) {
      return;
    }
    // 每次跨层级清除面板-- 性能优化
    map.value.removeLayer(geoarr.value);
    // 清除Layer组
    feiLineGroupLayer.value.clearLayers();
    feiMakerGroupLayer.value.clearLayers();
    // 遍历json
    json.forEach((item, index) => {
      let areaName = item.properties.name;
      let Areaitems =
        datasArr.value[datasArr.value.length - 1][
          areaName.replace(/(省|市|自治区|维吾尔自治区)$/g, '')
        ];
      let colors = Areaitems ?? '#008c8c';
      // 设置事件
      const onEachFeature = (feature, layer) => {
        layer.on({ 
          click: (e) => {
            // 点击
            let codes = e.target.feature.properties.adcode;
            let { name } = e.target.feature.properties;
            // 这里根据需求来，acroutes主要限制下钻的层级
            if (acroutes.value.length > 1) {
              return;
            } 
            // 处理特殊地图
            let prov =
              datasArr.value[datasArr.value.length - 1][
                name.replace(/(省|市|自治区|维吾尔自治区)$/g, '')
              ];
            let childrenArr = prov.children;
            let objs = {};
            // 更改provinces的值
            provinces.value = prov;
            childrenArr.map((item, index) => {
              objs[item.name] = item;
            });
            datasArr.value.push(objs);
            acroutes.value.push(codes);
            // 根据轮廓修正地图位置，以及缩放大小
            map.value.fitBounds(e.target.getBounds());
            // 根据地区的code请求geojson数据
            getGeoJson(`${codes}_full`).then((res) => {
              geoarr.value.clearLayers(geoarr.value);
                // 因为层级有限 可以考虑递归渲染 
                updateGeoJson(res);
            });
          },
        });
      }; 
      // 设置区域默认颜色+添加点击事件
      let geojson = L.geoJSON(item, {
        style: {
          weight: 2, //边框粗细
          opacity: 0.4, //透明度
          fillColor: 'transparent', //区域填充颜色
          fillOpacity: 0.3, //区域填充颜色的透明
        },
        onEachFeature: onEachFeature,
      });
     // 添加geo模块
      geoarr.value.addLayer(geojson);
    });
     // 添加将geoarr添加到地图中去
    map.value.addLayer(geoarr.value); 
  }
  return{
       initMap,
       updateGeoJson
  }
}

<template>
  <div id="map"></div>
</template>
<script lang="ts" setup>
// 插件可加载各种地图（如：智图地图，谷歌地图，高德地图等包含卫星地图）
import L from 'leaflet'; 
import 'leaflet/dist/leaflet.css';
import '@geoman-io/leaflet-geoman-free';
import '@geoman-io/leaflet-geoman-free/dist/leaflet-geoman.css';
import { getGeoJson } from '@/api/getGeoJson';
import { onMounted, unref } from '@vue/runtime-core';
import { defineExpose, defineEmits } from 'vue';
import { useLeaflet } from '@/lib/useLeaflet';
let { initMap, updateGeoJson  } = useLeaflet('map'); 
onMounted(() => { 
  initMap(
    {
      attributionControl: false, // 是否使用工具集 
      zoomAnimation: true,
      maxZoom: 13, 
      minZoom: 4,
      zoom: 4,
      worldCopyJump: true,
      markerZoomAnimation: true,
      zoomControl: false, 
    } 
  );
//   首先加载全国地图
  getGeoJson('100000_full').then((res) => {
   updateGeoJson(res);
  })
});
</script>