leaflet-image 导出图片

使用 leaflet 、leaflet-image、vue 截图并导出。

示例

提示

导出需要一些时间请稍后，正常会有一个 loading 来处理 🍵。

导出图片

安装依赖

# 截图导出图片插件
pnpm install leaflet-image

# 文件下载插件
pnpm install file-saver

项目引入

import leafletImage from "leaflet-image";

import { saveAs } from 'file-saver';

代码实现

index.vue

<script setup>
import { ref, defineAsyncComponent } from 'vue';
import leafletImage from 'leaflet-image';
import { saveAs } from 'file-saver';

const InitMap = defineAsyncComponent(() =>
  import('../../components/InitMapTianditu.vue')
);

/**
 * base64转图片
 * @param url
 * @param filename
 * @param mimeType
 * @return File
 */
const base64ToFile = (url, filename, mimeType) => {
  return fetch(url)
    .then(function (res) {
      return res.arrayBuffer();
    })
    .then(function (buf) {
      return new File([buf], filename, { type: mimeType });
    });
};

const mapObj = ref();

// 地图导出图片
const exportPicture = () => {
  leafletImage(mapObj.value, async (err, canvas) => {
    console.log(err);
    const fileBase64 = canvas.toDataURL();
    const file = await base64ToFile(fileBase64, '地图图片导出', 'png');

    saveAs(file, `地图图片导出.png`);
  });
};

const mapLoad = (map) => {
  mapObj.value = map;
};
</script>

<template>
  <init-map @map-load="mapLoad"></init-map>
  <p class="c-button" @click="exportPicture">导出图片</p>
</template>

<style scoped></style>

InitMapTianditu.vue

<script setup>
import { onMounted, onUnmounted, ref } from 'vue';
// todo 项目使用请放开 leaflet 引入
// import L from 'leaflet';

const props = defineProps({
  center: {
    type: Array,
    default: [32.0237855, 118.8075675]
  }
})

const emit = defineEmits(['mapLoad']);

const mapRef = ref();

const initMap = () => {
  const map = L.map(mapRef.value, {
    center: props.center,
    zoom: 11,
    minZoom: 6,
    maxZoom: 20
  });

  const mapType = 'vec';
  L.tileLayer(
    'https://t{s}.tianditu.gov.cn/' +
      mapType +
      '_w/wmts?SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=' +
      mapType +
      '&STYLE=default&TILEMATRIXSET=w&FORMAT=tiles&TILECOL={x}&TILEROW={y}&TILEMATRIX={z}&tk=b72aa81ac2b3cae941d1eb213499e15e',
    {
      subdomains: ['0', '1', '2', '3', '4', '5', '6', '7'],
      attribution:
        '&copy; <a href="http://lbs.tianditu.gov.cn/home.html">天地图 GS(2022)3124号 - 甲测资字1100471</a>'
    }
  ).addTo(map);

  const mapLabelType = 'cva';
  L.tileLayer(
    'https://t{s}.tianditu.gov.cn/' +
      mapLabelType +
      '_w/wmts?SERVICE=WMTS&REQUEST=GetTile&VERSION=1.0.0&LAYER=' +
      mapLabelType +
      '&STYLE=default&TILEMATRIXSET=w&FORMAT=tiles&TILECOL={x}&TILEROW={y}&TILEMATRIX={z}&tk=b72aa81ac2b3cae941d1eb213499e15e',
    {
      subdomains: ['0', '1', '2', '3', '4', '5', '6', '7']
    }
  ).addTo(map);

  // 地图初始化完成发送事件
  emit('mapLoad', map);

  return map;
};

const mapObj = ref();

// 在 onMounted 中初始化地图
onMounted(() => {
  mapObj.value = initMap();
});

const removeMap = () => {
  if (mapObj.value) {
    mapObj.value.remove();
  }
};

// 在组件卸载时删除地图
onUnmounted(() => {
  removeMap();
});
</script>

<template>
  <div ref="mapRef" class="map"></div>
</template>

<style scoped>
.map {
  height: 40vh;
  z-index: 0;
}
</style>

贡献者

vaebe

chengjinzhang