GPS坐標定位與距離計算

Android獲取當前位置（GPS和網絡定位）

1、比較：

GPS准確度高但耗電多，網絡定位耗電少但准確度低

2、代碼

①添加權限： 
AndroidManifest.xml：

<!-- 兩種provider的權限 -->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<!-- 僅網絡定位的權限 -->
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

 

---

②Java代碼：

public class MainActivity extends Activity {
    //定位都要通過LocationManager這個類實現
    private LocationManager locationManager;
    private String provider;

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

        if (list.contains(LocationManager.GPS_PROVIDER)) {
        //是否為GPS位置控制器
            provider = LocationManager.GPS_PROVIDER;
        } 
        else if (list.contains(LocationManager.NETWORK_PROVIDER)) {
        //是否為網絡位置控制器
            provider = LocationManager.NETWORK_PROVIDER;

        } else {
            Toast.makeText(this, "請檢查網絡或GPS是否打開",
                    Toast.LENGTH_LONG).show();
            return;
        }
        Location location = locationManager.getLastKnownLocation(provider);
        if (location != null) {
            //獲取當前位置，這里只用到了經緯度
            String string = "緯度為：" + location.getLatitude() + ",經度為："
                    + location.getLongitude();
        }

//綁定定位事件，監聽位置是否改變
//第一個參數為控制器類型第二個參數為監聽位置變化的時間間隔（單位：毫秒）
//第三個參數為位置變化的間隔（單位：米）第四個參數為位置監聽器        
locationManager.requestLocationUpdates(provider, 2000, 2,
                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
            // 更新當前經緯度
        }
    };
    //關閉時解除監聽器
    @Override
    protected void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        if (locationManager != null) {
            locationManager.removeUpdates(locationListener);
        }
    }

}

計算兩點地圖坐標的距離 C#  

private static double CalcMil(double X1, double Y1, double X2, double Y2)
        {
            double PI = 3.1415926535898;
            double EARTH_RADIUS = 6378137;  //地球半徑 

            double CurRadLong = 0;    //兩點經緯度的弧度
            double CurRadLat = 0;
            double PreRadLong = 0;
            double PreRadLat = 0;
            double a = 0, b = 0;              //經緯度弧度差
            double MilValue = 0;

            //將經緯度換算成弧度
            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;

            //計算經緯度差值
            if (CurRadLat > PreRadLat)
            {
                a = CurRadLat - PreRadLat;
            }
            else
            {
                a = PreRadLat - CurRadLat;
            }

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

            MilValue = 2 * 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;
        }

 

計算兩點地圖坐標的距離 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;    
    }    
    
    /**   
     * 通過經緯度獲取距離(單位：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;    
    }    
}