微信小程序地图(map)组件点击(tap)获取经纬度的方法

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。

代码如下:<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