微信小程序地图(map)组件点击(tap)获取经纬度

微信小程序中使用地图 (map) 组件，通过点击 (tap) 获取经纬度，按照官方的回应，暂时是没法做到的，从地图组件 API 多有残缺判断，怀疑是个实习生干的 …
做个变通，适用性有限，请大家参考。基本思路就是在地图上铺满一层 marker，从而通过点击 marker 获得经纬度。
<map id=”map” longitude=”102.324520″ latitude=”40.099994″ scale=”4″ bindcontroltap=”controltap” polygons=”{{polygons}}” bindregionchange=”regionchange” markers=”{{markers}}” bindmarkertap=”markertap” show-location style=”width: 100%; height: 700px;”></map>
const app = getApp()

const markersize = 30

function range(start, edge, step) {
for (var ret = [];
(edge – start) * step > 0; start += step) {
ret.push(start);
}
return ret;
}

function markers(northeast, southwest, scale, width, height) {

const markerslng = (northeast.longitude – southwest.longitude) * markersize / width
const markerslat = (northeast.latitude – southwest.latitude) * markersize / height

const maxlon = northeast.longitude
const minlon = southwest.longitude
const maxlat = northeast.latitude
const minlat = southwest.latitude

const lons = range(minlon, maxlon, markerslng)
const lats = range(minlat, maxlat, markerslat)

let _markers = []
lons.forEach((lon, i) => {
lats.forEach((lat, j) => {
_markers.push({
id: lon + ‘,’ + lat,
latitude: lat,
longitude: lon,
iconPath: ‘/marker.png’,
alpha: 0.1, // 将图片设置为透明, 通过开发者工具看不出效果, 但真机是有效果的
width: markersize,
height: markersize
})
})
})
return _markers
}

Page({
data: {
polygons: [],
controls: [{
id: 1,
position: {
left: 0,
top: 300 – 50,
width: 50,
height: 50
},
clickable: true
}],
markers: []
},
createMarkers() {

this.mapCtx = wx.createMapContext(‘map’)
const query = wx.createSelectorQuery()
const map = query.select(‘#map’).boundingClientRect()

let that = this

that.mapCtx.getRegion({
success(res1) {
that.mapCtx.getScale({
success(res2) {
query.exec((res) => {
let width = res[0].width;
let height = res[0].height;
let _markers = markers(res1.northeast, res1.southwest, res2.scale, width, height)
that.data.markers = _markers
that.setData(that.data)
})
}
})
}
})
},
regionchange(e) {
this.createMarkers()
},
markertap(e) {
console.log(e.markerId)
},
controltap(e) {
console.log(e.controlId)
},
onReady(e) {
this.createMarkers()
}
})
效果如图