Android 之 獲取地理位置及監聽

第一步、添加權限

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.INTERNET"/>

第二步、后台實現

public class MainActivity extends AppCompatActivity {

    private static final String TAG = "MainActivity";
    private LocationManager locationManager;
    private String locationProvider;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        locationManager = (LocationManager) getSystemService(getApplicationContext().LOCATION_SERVICE);
        //下面注釋的代碼獲取的location為null，所以采用Criteria的方式。
        /*List<String> providers = locationManager.getProviders(true);
        if (providers.contains(LocationManager.GPS_PROVIDER)) {
            //如果是GPS
            locationProvider = LocationManager.GPS_PROVIDER;
            Log.d(TAG, "onCreate: gps=" + locationProvider);
        } else if (providers.contains(LocationManager.NETWORK_PROVIDER)) {
            //如果是Network
            locationProvider = LocationManager.NETWORK_PROVIDER;
            Log.d(TAG, "onCreate: network=" + locationProvider);
        } else {
            Log.d(TAG, "onCreate: 沒有可用的位置提供器");
            Toast.makeText(this,"沒有可用的位置提供器",Toast.LENGTH_SHORT).show();
            return;
        }
        //獲取Location，老是獲取為空！所以用locationManager.getBestProvider(criteria, true);
        Location location = locationManager.getLastKnownLocation(locationProvider);
        */
        Criteria criteria = new Criteria();
        criteria.setAccuracy(Criteria.ACCURACY_COARSE);//低精度，如果設置為高精度，依然獲取不了location。
        criteria.setAltitudeRequired(false);//不要求海拔
        criteria.setBearingRequired(false);//不要求方位
        criteria.setCostAllowed(true);//允許有花費
        criteria.setPowerRequirement(Criteria.POWER_LOW);//低功耗

        //從可用的位置提供器中，匹配以上標准的最佳提供器
        locationProvider = locationManager.getBestProvider(criteria, true);
        if (ActivityCompat.checkSelfPermission(getApplicationContext(), 
　　　　　　Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getApplicationContext(), 
　　　　　　Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            Log.d(TAG, "onCreate: 沒有權限 ");
            return;
        }
        Location location = locationManager.getLastKnownLocation(locationProvider);
        Log.d(TAG, "onCreate: " + (location == null) + "..");
        if (location != null) {
            Log.d(TAG, "onCreate: location");
            //不為空,顯示地理位置經緯度
            showLocation(location);
        }
        //監視地理位置變化
        locationManager.requestLocationUpdates(locationProvider, 0, 0, locationListener);
    }

    /**
     * LocationListern監聽器
     * 參數：地理位置提供器、監聽位置變化的時間間隔、位置變化的距離間隔、LocationListener監聽器
     */

    LocationListener locationListener = new LocationListener() {

        @Override
        public void onStatusChanged(String provider, int status, Bundle arg2) {

        }

        @Override
        public void onProviderEnabled(String provider) {
            Log.d(TAG, "onProviderEnabled: " + provider + ".." + Thread.currentThread().getName());
        }

        @Override
        public void onProviderDisabled(String provider) {
            Log.d(TAG, "onProviderDisabled: " + provider + ".." + Thread.currentThread().getName());
        }

        @Override
        public void onLocationChanged(Location location) {
            Log.d(TAG, "onLocationChanged: " + ".." + Thread.currentThread().getName());
            //如果位置發生變化,重新顯示
            showLocation(location);
        }
    };

    private void showLocation(Location location) {
        Log.d(TAG,"定位成功------->"+"location------>經度為：" + location.getLatitude() + "\n緯度為" + location.getLongitude());
    }
}