我需要存储圈的所有经纬度点绘制在谷歌地图。喜欢 ：

I need to store all the LatLng points of circle drawn on google map. like :

我有圆圈，半径（以米）。如何获得的？我试着用code ......

I have circle and radius(in meter). How to get that?. i tried with the code......

 private ArrayList<LatLng> makeCircle(LatLng centre, double radius, float zoom)
 {
     ArrayList<LatLng> points = new ArrayList<LatLng>();
     LatLngBounds.Builder builder = new LatLngBounds.Builder();

     double EARTH_RADIUS = 6378100.0;

     for (double t = 0; t <= Math.PI * 2; t += 1.0)
     {
         double rad = radius + zoom * EARTH_RADIUS;
         double latPoint = centre.latitude + (rad / EARTH_RADIUS) * Math.sin(t);
         double lonPoint = centre.longitude + (rad / EARTH_RADIUS) * Math.cos(t) / Math.cos(centre.latitude);
         points.add(new LatLng(latPoint * 180.0 / Math.PI, lonPoint * 180.0 / Math.PI));
         Marker customMarker = map.addMarker(new MarkerOptions()
        .position(new LatLng(latPoint,lonPoint)));

         builder.include(new LatLng(latPoint,lonPoint));

         LatLngBounds bound = builder.build();
         CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bound, width-100, height-100, 20);
         map.animateCamera(cu);
     }
     return points;
 }

但即时得到积分，但不是确切位置。我得到这个

but i m getting points but not on exact locations. i am getting this

如何解决此问题？

推荐答案

在放大的因素是不相关的这里的计算。更新您的makeCircle（）方法，如下图所示，它会工作正是你想要的方式：

The 'zoom' factor is not relevant for the calculations here. Update your makeCircle() method as shown below and it will work exactly the way you want:

private ArrayList<LatLng> makeCircle(LatLng centre, double radius) 
    { 
    ArrayList<LatLng> points = new ArrayList<LatLng>(); 

    double EARTH_RADIUS = 6378100.0; 
    // Convert to radians. 
    double lat = centre.latitude * Math.PI / 180.0; 
    double lon = centre.longitude * Math.PI / 180.0; 

    for (double t = 0; t <= Math.PI * 2; t += 0.3) 
    { 
    // y 
    double latPoint = lat + (radius / EARTH_RADIUS) * Math.sin(t); 
    // x 
    double lonPoint = lon + (radius / EARTH_RADIUS) * Math.cos(t) / Math.cos(lat);

    // saving the location on circle as a LatLng point
    LatLng point =new LatLng(latPoint * 180.0 / Math.PI, lonPoint * 180.0 / Math.PI);

    // here mMap is my GoogleMap object 
    mMap.addMarker(new MarkerOptions().position(point));

    // now here note that same point(lat/lng) is used for marker as well as saved in the ArrayList 
    points.add(point);

    } 

    return points; 
    }

我相信它帮助你：）

I am sure it helped you :)