问RxAndroidBLE :在没有服务发现的情况下启用特征通知

EN

private void onConnectionReceived(RxBleConnection rxBleConnection) {

        rxBleConnection.discoverServices()
                .flatMap(rxBleDeviceServices -> {
                    return rxBleDeviceServices.getCharacteristic(MY_UUID_RX);
                })
                .flatMapObservable(bluetoothGattCharacteristic -> {
                    BluetoothGattDescriptor cccDescriptor = bluetoothGattCharacteristic.getDescriptor(CLIENT_CHARACTERISTIC_CONFIGURATION_UUID);
                    Completable enableNotificationCompletable = rxBleConnection.writeDescriptor(cccDescriptor, BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
                    Completable disableNotificationCompletable = rxBleConnection.writeDescriptor(cccDescriptor, BluetoothGattDescriptor.DISABLE_NOTIFICATION_VALUE).onErrorComplete();
                    return rxBleConnection.setupNotification(bluetoothGattCharacteristic, NotificationSetupMode.COMPAT)
                            .doOnNext(notificationObservable -> notificationHasBeenSetUp())
                            .flatMap(notificationObservable -> notificationObservable)
                            .mergeWith(enableNotificationCompletable)
                            .doOnDispose(disableNotificationCompletable::subscribe); // fire and forget
                })
                .observeOn(AndroidSchedulers.from(handlerThread.getLooper()))
                .subscribe(this::onNotificationReceived, this::onNotificationSetupFailure);
    }