Android BLE:成功将ENABLE\u NOTIFICATION\u VALUE写入BluetoothGattDescriptor,但onCharacteristicChanged从未触发

    boolean success = mBluetoothGatt.setCharacteristicNotification(characteristic, true);
    Log.e(TAG, "set char notification = " + (success ? "It worked :)" : "It did not work :("));

    if (UUID_DATA_PACKET.equals(characteristic.getUuid())) {
        BluetoothGattDescriptor descriptor = characteristic.getDescriptor(
                UUID.fromString(EkoCoreGattAttributes.CLIENT_CHARACTERISTIC_CONFIG));

        descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);

        success = mBluetoothGatt.writeDescriptor(descriptor);
        Log.e(TAG, "set descriptor = " + descriptor.getCharacteristic().getWriteType() + ", success = " + (success ? "It worked :)" : "It did not work :("));
    }