androidはブロードキャスト受信機でネットワークの変化状態を判断する

	private BroadcastReceiver NetWorkStateReceiver = new BroadcastReceiver() {

		@Override
		public void onReceive(Context context, Intent intent) {

			if (intent.getAction().equals(
					ConnectivityManager.CONNECTIVITY_ACTION)) {
				connectivityManager = (ConnectivityManager) context
						.getSystemService(Context.CONNECTIVITY_SERVICE);
				info = connectivityManager.getActiveNetworkInfo();
				if (info != null && info.isAvailable()) {
					Log.d("liu", "  ");

				} else {
					Log.d("liu", "     ");
				}
			} else {
				Log.i("liu", "     ");
			}
		}

	};

最後に忘れないでください.権限を追加します.