How to get the LatLngBounds of a Circle in Google

问题:

How can I get the Northeast and Southwest coordinates of a Circle with a given center and radius? I can't find any solution anywhere. Currently, the Circle object doesn't have getLatLngBounds() nor getBounds() methods unlike before.

回答1:

You can use the SphericalUtil.computeOffset method from the Google Maps Android API Utility Library. To use it you need to the following dependency to your build.gradle:

dependencies {
    compile 'com.google.maps.android:android-maps-utils:0.4+'
}

Then, you can calculate the northeast and southwest coordinates of your circle doing:

double radius = 104.52;
LatLng center = new LatLng(40.22861, -3.95567);

LatLng targetNorthEast = SphericalUtil.computeOffset(center, radius * Math.sqrt(2), 45);
LatLng targetSouthWest = SphericalUtil.computeOffset(center, radius * Math.sqrt(2), 225);

回答2:

Essentially copying and pasting antonio's answer:

    public static LatLngBounds getLatLngBoundsFromCircle(Circle circle){
        if(circle != null){
            return new LatLngBounds.Builder()
                    .include(SphericalUtil.computeOffset(circle.getCenter(), circle.getRadius() * Math.sqrt(2), 45))
                    .include(SphericalUtil.computeOffset(circle.getCenter(), circle.getRadius() * Math.sqrt(2), 225))
                    .build();
        }
        return null;
    }