leaflet 实现地图搜索周边功能

/**

* 地图点位-站点搜索周边

*/

async getStationAroundData(content, { ctx, userid }) {

let { jd = "0", wd = "0",distance } = content;

// distance 距离是m为单位

let jd_new = jd,

wd_new = wd;

const allStation=await this.airjgMapDetail({code:440000});

let list = [];

for(let item of allStation){

item.distance = this.algorithm([wd_new, jd_new], [item.lat, item.lng]);

if (item.distance > distance) continue;

list.push(item);

}

list = list.sort((a, b) => a.distance - b.distance);

list.forEach((v, index) => {

v.index = ++index;

v.zj = v._id;

});

  


return list;

}

  


//  计算两点之间直线距离

algorithm(point1, point2) {

let [x1, y1] = point1;

let [x2, y2] = point2;

let Lat1 = this.rad(x1); // 纬度

let Lat2 = this.rad(x2);

let a = Lat1 - Lat2; // 两点纬度之差

let b = this.rad(y1) - this.rad(y2); // 经度之差

let s =

2 *

Math.asin(

Math.sqrt(Math.pow(Math.sin(a / 2), 2) + Math.cos(Lat1) * Math.cos(Lat2) * Math.pow(Math.sin(b / 2), 2))

);

//  计算两点距离的公式

s = s * 6378137.0; // 弧长等于弧度乘地球半径（半径为米）

s = Math.round(s * 10000) / 10000; // 精确距离的数值

return s;

}

//将用角度表示的角特换为近似想等的用弧度表示的角 java Math.toRadians

rad(d) {

return (d * Math.PI) / 180.0;

}