Android 如何使用location.distanceTo()

我正在使用片段，我需要获取当前位置（纬度和经度） 我需要用目的地位置来计算我当前的位置。

你能帮我一下吗？计算位置的最佳方法是什么：

如何使用 lat 和 lng 获取当前位置和目的地位置的距离；

    LocationManager locationManager;
    Location locatio;



locationManager = (LocationManager)getActivity().getSystemService(Context.LOCATION_SERVICE);

location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);





String product_latitude     = "3.121191";
            String product_longtitude   = "101.673298";

            Double latitude     = Double.valueOf(product_latitude);
            Double longtitude   = Double.valueOf(product_longtitude);

            // Calculate the Distance
            String product_distance = location.distanceTo(latitude, longtitude);

Try this

double latitude=lat;
double longitude=lng;    
float distance=0;
Location crntLocation=new Location("crntlocation");
crntLocation.setLatitude(currentLatitude);
crntLocation.setLongitude(currentLongitude);

Location newLocation=new Location("newlocation");
newLocation.setLatitude(latitude);
newLocation.setLongitude(longitude);


//float distance = crntLocation.distanceTo(newLocation);  in meters
distance =crntLocation.distanceTo(newLocation) / 1000; // in km