Android中如何監聽GPS開啓和關閉

有時須要監聽GPS的開關(這種需求並很少見)。實現的思路是監聽表明 GPS 開關的 URI 的數據是否有發生變化

GPS的開關是系統設置，android.provider.Settings.Secure 表明了app能夠讀取但不能修改的系統設置。能夠從這個類中獲取到表明GPS開關的URI。

關鍵代碼以下

getContentResolver()
			.registerContentObserver(
					Settings.Secure
							.getUriFor(Settings.System.LOCATION_PROVIDERS_ALLOWED),
					false, mGpsMonitor);

完整的代碼以下：

public class MyActivity extends Activity {

	private final ContentObserver mGpsMonitor = new ContentObserver(null) {
		@Override
		public void onChange(boolean selfChange) {
			super.onChange(selfChange);

			boolean enabled = mLocationManager
					.isProviderEnabled(LocationManager.GPS_PROVIDER);
			System.out.println("gps enabled? " + enabled);
		}
	};

	private LocationManager mLocationManager;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		mLocationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
	}

	protected void onStart() {
		getContentResolver()
				.registerContentObserver(
						Settings.Secure
								.getUriFor(Settings.System.LOCATION_PROVIDERS_ALLOWED),
						false, mGpsMonitor);
	};

	@Override
	protected void onStop() {
		super.onStop();
		getContentResolver().unregisterContentObserver(mGpsMonitor);
	}
}