Principle reference link
js how to judge that a point on the map is within the polygon
uniapp realizes electronic fence
<map class="my_map" id="myMap" show-location :latitude="latitude" :longitude="longitude" :markers="markers"
:scale="mapScale" @regionchange="regionChange" @begin="begin" @end="end" @updated="mapUpDate"
:subkey="null" :polygons="polygons">
</map>
data() {
return {
polygons: [
{
points: [{
latitude: 29.600936,
longitude: 106.513925,
},
{
latitude: 29.601398,
longitude: 106.515609
},
{
latitude: 29.600997,
longitude: 106.51724
},
{
latitude: 29.602219,
longitude: 106.517466
},
{
latitude: 29.602121,
longitude: 106.515524
},
{
latitude: 29.60103,
longitude: 106.513914
},
],
strokeColor: "#FD302F",
strokeWidth: 2,
fillColor: "green"
}
], // 通过后端请求电子围栏经纬度集合
}
}
// 拖动地图后获取当前中心点的地图坐标
getCenterLoaction() {
this.mapCtx.getCenterLocation({
success: res => {
// 更新地址信息
// 如果存在多个电子围栏则去遍历该方法，判断是否在电子围栏范围内
const isArea = this.isPointInPolygon(res.longitude, res.latitude, this.polygons[0].points)
console.log('是否在电子围栏范围内', isArea)
}
});
},
// 判断点是否在多边形范围内
isPointInPolygon(lng, lat, polygon) {
console.log(polygon)
var cnt = 0;
for (var i = 0; i < polygon.length; i++) {
const g = lng;
const t = lat;
const p1g = polygon[i].longitude;
const p1t = polygon[i].latitude;
const p2g = polygon[i === polygon.length - 1 ? 0 : i + 1].longitude;
const p2t = polygon[i === polygon.length - 1 ? 0 : i + 1].latitude;
const ming = Math.min(p1g, p2g);
const maxg = Math.max(p1g, p2g);
const mint = Math.min(p1t, p2t);
const maxt = Math.max(p1t, p2t);
if ((mint <= t && t <= maxt && ming <= g) && (maxg <= g || (p2g + (p1g - p2g) * ((t - p2t) / (p1t -
p2t)) < g))) {
cnt++
}
}
return cnt % 2 === 1;
},