Android-计算每个缩放级别（例如Gmaps比例尺）的地图距离

Question

I got zoom level of 3-21. zoom out-zoom in respectively.

But i want to compute that zoom level to meter/km distance with the given bar(screenwidth?) of the screen like Gmaps scale bar do.

Example :

zoom level 20 = hundreds of meter
zoom levevl 3 = thousands of km or a mile

TIA

Answer 1

You can find the radius between right/left most point and center of the map when map becomes idle by using

/**
 * Method used to fetch Map radius
 */
private int getMapRadius() {
    LatLng latlng = googleMap.getProjection().getVisibleRegion().latLngBounds.getCenter();
    if (latLng == null)
        return 0;
    LatLng latLng1 = googleMap.getProjection().getVisibleRegion().farRight;
    return (int) MapUtils.computeDistance(latLng1.latitude, latLng1.longitude, latLng.latitude, latLng.longitude);
}