GPS坐标定位与距离计算

Android获取当前位置（GPS和网络定位）

1、比较：

GPS准确度高但耗电多，网络定位耗电少但准确度低

2、代码

①添加权限： 
AndroidManifest.xml：

<!-- 两种provider的权限 -->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<!-- 仅网络定位的权限 -->
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

---

②Java代码：

public class MainActivity extends Activity {
    //定位都要通过LocationManager这个类实现
    private LocationManager locationManager;
    private String provider;

    @SuppressWarnings("static-access")
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //获取定位服务
        locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        //获取当前可用的位置控制器
        List<String> list = locationManager.getProviders(true);

        if (list.contains(LocationManager.GPS_PROVIDER)) {
        //是否为GPS位置控制器
            provider = LocationManager.GPS_PROVIDER;
        }
        else if (list.contains(LocationManager.NETWORK_PROVIDER)) {
        //是否为网络位置控制器
            provider = LocationManager.NETWORK_PROVIDER;

        } else {
            Toast.makeText(this, "请检查网络或GPS是否打开",
                    Toast.LENGTH_LONG).show();
            return;
        }
        Location location = locationManager.getLastKnownLocation(provider);
        if (location != null) {
            //获取当前位置，这里只用到了经纬度
            String string = "纬度为：" + location.getLatitude() + ",经度为："
                    + location.getLongitude();
        }

//绑定定位事件，监听位置是否改变
//第一个参数为控制器类型第二个参数为监听位置变化的时间间隔（单位：毫秒）
//第三个参数为位置变化的间隔（单位：米）第四个参数为位置监听器
locationManager.requestLocationUpdates(provider, , ,
                locationListener);

    }

    LocationListener locationListener = new LocationListener() {

        @Override
        public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onProviderEnabled(String arg0) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onProviderDisabled(String arg0) {
            // TODO Auto-generated method stub

        }

        @Override
        public void onLocationChanged(Location arg0) {
            // TODO Auto-generated method stub
            // 更新当前经纬度
        }
    };
    //关闭时解除监听器
    @Override
    protected void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        if (locationManager != null) {
            locationManager.removeUpdates(locationListener);
        }
    }

}

计算两点地图坐标的距离 C#

private static double CalcMil(double X1, double Y1, double X2, double Y2)
        {
            double PI = 3.1415926535898;
            double EARTH_RADIUS = ;  //地球半径 

            double CurRadLong = ;    //两点经纬度的弧度
            double CurRadLat = ;
            double PreRadLong = ;
            double PreRadLat = ;
            double a = , b = ;              //经纬度弧度差
            double MilValue = ;

            //将经纬度换算成弧度
            CurRadLong = (double)(X1);
            CurRadLong = CurRadLong * PI / 180.0;

            PreRadLong = (double)(X2);
            PreRadLong = PreRadLong * PI / 180.0;

            CurRadLat = (double)(Y1);
            CurRadLat = CurRadLat * PI / 180.0f;

            PreRadLat = (double)(Y2);
            PreRadLat = PreRadLat * PI / 180.0f;

            //计算经纬度差值
            if (CurRadLat > PreRadLat)
            {
                a = CurRadLat - PreRadLat;
            }
            else
            {
                a = PreRadLat - CurRadLat;
            }

            if (CurRadLong > PreRadLong)
            {
                b = CurRadLong - PreRadLong;
            }
            else
            {
                b = PreRadLong - CurRadLong;
            }

            MilValue =  * Math.Asin(Math.Sqrt(Math.Sin(a / 2.0) * Math.Sin(a / 2.0) + Math.Cos(CurRadLat) * Math.Cos(PreRadLat) * Math.Sin(b / 2.0) * Math.Sin(b / 2.0)));
            MilValue = (double)(EARTH_RADIUS * MilValue);
            return MilValue;
        }

计算两点地图坐标的距离 Java

/**
 * Created by yuliang on 2015/3/20.
 */
public class LocationUtils {
    private static double EARTH_RADIUS = 6378.137;    

    private static double rad(double d) {
        return d * Math.PI / 180.0;
    }    

    /**
     * 通过经纬度获取距离(单位：米)
     * @param lat1
     * @param lng1
     * @param lat2
     * @param lng2
     * @return
     */
    public static double getDistance(double lat1, double lng1, double lat2,
                                     double lng2) {
        double radLat1 = rad(lat1);
        double radLat2 = rad(lat2);
        double a = radLat1 - radLat2;
        double b = rad(lng1) - rad(lng2);
        double s = 2 * Math.asin(Math.sqrt(Math.pow(Math.sin(a / 2), 2)
                + Math.cos(radLat1) * Math.cos(radLat2)
                * Math.pow(Math.sin(b / 2), 2)));
        s = s * EARTH_RADIUS;
        s = Math.round(s * 10000d) / 10000d;
        s = s*1000;
        return s;
    }
}