我正在使用 RxAndroidBle 库与蓝牙设备进行通信，但是最近我遇到了一个奇怪的问题。读取设备特性之一时，我收到这样的错误：
BleGattCharacteristicException{macAddress=60:CE:32:BA:9E:70,
status=6 (0x06 -> https://android.googlesource.com/platform/external/bluetooth/bluedroid/+/android-5.1.0_r1/stack/include/gatt_api.h),
bleGattOperationType=BleGattOperation{description='CHARACTERISTIC_READ'}}
我看到描述表明特征读取有问题，但我能够使用一些商业扫描仪或谷歌样本中的香草蓝牙代码在同一设备上读取它。我检查了特征属性 - 它有 PROPERTY_READ。
在使用 RxAndroidBle 的 Polidea 示例时，我遇到了同样的错误。
在互联网上的任何地方都找不到类似的案例，也许有人遇到了这样的错误。附加信息可能是我连接的设备是在 iPhone 上运行的 ble 设备模拟器。我没有提供任何片段，因为我使用的是核心示例中的相同代码。
完整的详细日志：
06-12 11:00:20.105 22459-22459/? D/RxBle#Radio: QUEUED RxBleRadioOperationConnect(121589482)
06-12 11:00:20.106 22459-22504/? D/RxBle#Radio: STARTED RxBleRadioOperationConnect(121589482)
06-12 11:00:20.131 22459-22459/? D/BluetoothGatt: connect() - device: 41:0A:AE:0E:C2:50, auto: false
06-12 11:00:20.131 22459-22459/? D/BluetoothGatt: registerApp()
06-12 11:00:20.131 22459-22459/? D/BluetoothGatt: registerApp() - UUID=b6c1ef8f-408b-4afb-8e27-97a6ff2c20fb
06-12 11:00:20.137 22459-22473/? D/BluetoothGatt: onClientRegistered() - status=0 clientIf=6
06-12 11:00:20.330 22459-22473/? D/BluetoothGatt: onClientConnectionState() - status=0 clientIf=6 device=41:0A:AE:0E:C2:50
06-12 11:00:20.333 22459-22473/? D/RxBle#BluetoothGatt: onConnectionStateChange newState=2 status=0
06-12 11:00:20.395 22459-22854/? D/CharacteristicOperationExampleActivity: Hey, connection has been established!
06-12 11:00:20.400 22459-22504/? D/RxBle#Radio: FINISHED RxBleRadioOperationConnect(121589482)
06-12 11:00:25.608 22459-22459/? I/ViewRootImpl: ViewRoot's Touch Event : ACTION_DOWN
06-12 11:00:25.663 22459-22459/? I/ViewRootImpl: ViewRoot's Touch Event : ACTION_UP
06-12 11:00:25.675 22459-22459/? D/RxBle#Radio: QUEUED RxBleRadioOperationServicesDiscover(3295555)
06-12 11:00:25.676 22459-22504/? D/RxBle#Radio: STARTED RxBleRadioOperationServicesDiscover(3295555)
06-12 11:00:25.683 22459-22459/? D/BluetoothGatt: discoverServices() - device: 41:0A:AE:0E:C2:50
06-12 11:00:25.726 22459-22473/? D/BluetoothGatt: onSearchComplete() = Device=41:0A:AE:0E:C2:50 Status=0
06-12 11:00:25.727 22459-22473/? D/RxBle#BluetoothGatt: onServicesDiscovered status=0
06-12 11:00:25.732 22459-22854/? D/RxBle#Radio: QUEUED RxBleRadioOperationCharacteristicRead(177013014)
06-12 11:00:25.733 22459-22504/? D/RxBle#Radio: FINISHED RxBleRadioOperationServicesDiscover(3295555)
06-12 11:00:25.735 22459-22504/? D/RxBle#Radio: STARTED RxBleRadioOperationCharacteristicRead(177013014)
06-12 11:00:25.827 22459-22471/? W/BluetoothGatt: onCharacteristicRead() - Device=41:0A:AE:0E:C2:50 handle=102 Status=6
06-12 11:00:25.830 22459-22471/? D/RxBle#BluetoothGatt: onCharacteristicRead characteristic=1f26b1a4-2b50-11e7-99a8-fcaa142b0bea status=6
06-12 11:00:25.844 22459-22471/? D/RxBle#Radio: QUEUED RxBleRadioOperationDisconnect(84936079)
06-12 11:00:25.849 22459-22471/? D/elo: error: BleGattCharacteristicException{macAddress=41:0A:AE:0E:C2:50, status=6 (0x06 -> https://android.googlesource.com/platform/external/bluetooth/bluedroid/+/android-5.1.0_r1/stack/include/gatt_api.h), bleGattOperationType=BleGattOperation{description='CHARACTERISTIC_READ'}}
06-12 11:00:25.879 22459-22504/? D/RxBle#Radio: FINISHED RxBleRadioOperationCharacteristicRead(177013014)
06-12 11:00:25.880 22459-22504/? D/RxBle#Radio: STARTED RxBleRadioOperationDisconnect(84936079)
06-12 11:00:25.915 22459-22459/? D/elo: error: BleGattCharacteristicException{macAddress=41:0A:AE:0E:C2:50, status=6 (0x06 -> https://android.googlesource.com/platform/external/bluetooth/bluedroid/+/android-5.1.0_r1/stack/include/gatt_api.h), bleGattOperationType=BleGattOperation{description='CHARACTERISTIC_READ'}}
06-12 11:00:25.925 22459-22459/? D/BluetoothManager: getConnectionState()
06-12 11:00:25.925 22459-22459/? D/BluetoothManager: getConnectedDevices
06-12 11:00:25.951 22459-22459/? D/BluetoothGatt: cancelOpen() - device: 41:0A:AE:0E:C2:50
06-12 11:00:25.962 22459-22471/? D/BluetoothGatt: onClientConnectionState() - status=0 clientIf=6 device=41:0A:AE:0E:C2:50
06-12 11:00:25.966 22459-22471/? D/RxBle#BluetoothGatt: onConnectionStateChange newState=0 status=0
06-12 11:00:25.971 22459-22459/? D/BluetoothGatt: close()
06-12 11:00:25.971 22459-22459/? D/BluetoothGatt: unregisterApp() - mClientIf=6
06-12 11:00:25.974 22459-22504/? D/RxBle#Radio: FINISHED RxBleRadioOperationDisconnect(84936079)
来自 Google 蓝牙示例应用程序的详细日志，我可以在其中读取该属性
06-12 14:43:36.540 10869-10869/com.example.android.bluetoothlegatt I/ViewRootImpl: ViewRoot's Touch Event : ACTION_DOWN
06-12 14:43:36.598 10869-10869/com.example.android.bluetoothlegatt I/ViewRootImpl: ViewRoot's Touch Event : ACTION_UP
06-12 14:43:36.599 10869-10869/com.example.android.bluetoothlegatt D/BluetoothLeService: Trying to use an existing mBluetoothGatt for connection.
06-12 14:43:41.209 10869-10869/com.example.android.bluetoothlegatt D/BluetoothAdapter: stopLeScan()
06-12 14:43:41.215 10869-10869/com.example.android.bluetoothlegatt D/BluetoothAdapter: scan not started yet
06-12 14:43:43.781 10869-10882/com.example.android.bluetoothlegatt D/BluetoothGatt: onClientConnectionState() - status=0 clientIf=6 device=5F:56:F7:E9:8A:38
06-12 14:43:43.789 10869-10882/com.example.android.bluetoothlegatt I/BluetoothLeService: Connected to GATT server.
06-12 14:43:43.789 10869-10882/com.example.android.bluetoothlegatt D/BluetoothGatt: discoverServices() - device: 5F:56:F7:E9:8A:38
06-12 14:43:43.792 10869-10882/com.example.android.bluetoothlegatt I/BluetoothLeService: Attempting to start service discovery:true
06-12 14:43:45.513 10869-10882/com.example.android.bluetoothlegatt D/BluetoothGatt: onSearchComplete() = Device=5F:56:F7:E9:8A:38 Status=0
06-12 14:43:54.958 10869-10869/com.example.android.bluetoothlegatt D/BluetoothGatt: setCharacteristicNotification() - uuid: 1f26b1a4-2b50-11e7-99a8-fcaa142b0bea enable: true
06-12 14:43:55.063 10869-10882/com.example.android.bluetoothlegatt W/BluetoothGatt: onCharacteristicRead() - Device=5F:56:F7:E9:8A:38 handle=110 Status=0
确实存在差异，因为此应用程序在读取值之前设置通知。负责此操作的应用程序中的代码如下所示：
// If a given GATT characteristic is selected, check for supported features. This sample
// demonstrates 'Read' and 'Notify' features. See
// http://d.android.com/reference/android/bluetooth/BluetoothGatt.html for the complete
// list of supported characteristic features.
private final ExpandableListView.OnChildClickListener servicesListClickListner =
new ExpandableListView.OnChildClickListener() {
@Override
public boolean onChildClick(ExpandableListView parent, View v, int groupPosition,
int childPosition, long id) {
if (mGattCharacteristics != null) {
final BluetoothGattCharacteristic characteristic =
mGattCharacteristics.get(groupPosition).get(childPosition);
final int charaProp = characteristic.getProperties();
if ((charaProp | BluetoothGattCharacteristic.PROPERTY_READ) > 0) {
// If there is an active notification on a characteristic, clear
// it first so it doesn't update the data field on the user interface.
if (mNotifyCharacteristic != null) {
mBluetoothLeService.setCharacteristicNotification(
mNotifyCharacteristic, false);
mNotifyCharacteristic = null;
}
mBluetoothLeService.readCharacteristic(characteristic);
}
if ((charaProp | BluetoothGattCharacteristic.PROPERTY_NOTIFY) > 0) {
mNotifyCharacteristic = characteristic;
mBluetoothLeService.setCharacteristicNotification(
characteristic, true);
}
return true;
}
return false;
}
};
至于 RxAndroidBle 版本，我在 1.2.0、1.2.4 和 1.3.0 上测试过。Android 版本 7.1、6.0.1 和 5.1。
将尝试在读取特征之前实现此通知，因为这是我能看到的唯一区别。