修改公众号关注逻辑，增加电子围栏

utils/address.js

@@ -0,0 +1,13 @@
+// 计算距离   
+export const getDistance = (la1, lo1, la2, lo2) => { // 当前的纬度，当前的经度，接口拿到的纬度，接口拿到的经度
+    let La1 = la1 * Math.PI / 180.0;
+    let La2 = la2 * Math.PI / 180.0;
+    let La3 = La1 - La2;
+    let Lb3 = lo1 * Math.PI / 180.0 - lo2 * Math.PI / 180.0;
+    let distance = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(La3 / 2), 2) + Math.cos(La1) * Math.cos(La2) *
+      Math.pow(Math.sin(Lb3 / 2), 2)));
+    distance = distance * 6378.137;
+    distance = Math.round(distance * 10000) / 10000;
+    return distance;
+  }
+