我正在使用RxAndroidBle库：
此代码正常运行，点击UI上的Connect按钮，它建立了连接。
当我想在设备返回范围时自动连接到设备时出现问题。我不想再次点击“连接”按钮。
有没有这样的功能？ 'true'旗帜在这里帮助我，如果是的话，如何实施它？建议请。 rxBleDevice.establishConnection(true);
如果我使用rxBleDevice.establishConnection(true)而不是'false'，我会收到以下错误，请提供帮助：
RxBleLog.setLogLevel(RxBleLog.VERBOSE);
scanSubscription = rxBleClient.scanBleDevices(
new ScanSettings.Builder()
.setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
.setCallbackType(ScanSettings.CALLBACK_TYPE_ALL_MATCHES)
.build(),
new ScanFilter.Builder().setDeviceName("mydevice").build()
).take(1).subscribe(
scanResult -> {
final RxBleDevice rxBleDevice = scanResult.getBleDevice();
// connect to device
final Observable<RxBleConnection> connection = rxBleDevice.establishConnection(false);
connection
.subscribe(rxBleConnection -> {
DeviceInformation deviceInformation = new DeviceInformation();
deviceInformation.setName(rxBleDevice.getName());
scanSubscription.unsubscribe();
},
throwable -> {
throwable.printStackTrace();
System.out.println(throwable);
}
);
}
);
false
------
D/RxBle#ClientOperationQueue: QUEUED ScanOperationApi21(226148850)
D/RxBle#ClientOperationQueue: STARTED ScanOperationApi21(226148850)
I/Choreographer: Skipped 240 frames! The application may be doing too much work on its main thread.
I/RxBle#QueueOperation: Scan operation is requested to start.
D/BluetoothLeScanner: onClientRegistered() - status=0 clientIf=6
D/RxBle#ClientOperationQueue: FINISHED ScanOperationApi21(226148850)
D/BluetoothLeScanner: onScanResult() - ScanResult{mDevice=6F:AE:DE:3E:2E:C3, mScanRecord=ScanRecord [mAdvertiseFlags=26, mServiceUuids=[00001805], mManufacturerSpecificData={}, mServiceData={}, mTxPowerLevel=-2147483648, mDeviceName=101-1], mRssi=-92, mTimestampNanos=1043849718860030}
D/RxBle#ClientOperationQueue: QUEUED ConnectOperation(890174706)
D/RxBle#ClientOperationQueue: STARTED ConnectOperation(890174706)
V/RxBle#BleConnectionCompat: Connecting without reflection
D/BluetoothGatt: connect() - device: 6F:AE:DE:3E:2E:C3, auto: false
D/BluetoothGatt: registerApp()
D/BluetoothGatt: registerApp() - UUID=542bd417
D/BluetoothGatt: onClientRegistered() - status=0 clientIf=7
D/BluetoothGatt: onClientConnectionState() - status=0 clientIf=7 device=6F:AE:DE:3E:2E:C3
D/RxBle#BluetoothGatt: onConnectionStateChange newState=2 status=0
D/RxBle#ClientOperationQueue: FINISHED ConnectOperation(890174706)
I/RxBle#CancellableSubscription: Scan operation is requested to stop.
D/RxBle#ConnectionOperationQueue: QUEUED ServiceDiscoveryOperation(888759094)
D/RxBle#ConnectionOperationQueue: STARTED ServiceDiscoveryOperation(888759094)
D/BluetoothGatt: discoverServices() - device: 6F:AE:DE:3E:2E:C3
D/BluetoothGatt: onSearchComplete() = Device=6F:AE:DE:3E:2E:C3 Status=0
D/RxBle#BluetoothGatt: onServicesDiscovered status=0
D/BluetoothGatt: setCharacteristicNotification() - uuid: b31e89de enable: true
D/RxBle#ConnectionOperationQueue: FINISHED ServiceDiscoveryOperation(888759094)
true
------
D/RxBle#ClientOperationQueue: QUEUED ScanOperationApi21(226148850)
D/RxBle#ClientOperationQueue: STARTED ScanOperationApi21(226148850)
I/Choreographer: Skipped 207 frames! The application may be doing too much work on its main thread.
I/RxBle#QueueOperation: Scan operation is requested to start.
D/BluetoothLeScanner: onClientRegistered() - status=0 clientIf=6
D/RxBle#ClientOperationQueue: FINISHED ScanOperationApi21(226148850)
D/BluetoothLeScanner: onScanResult() - ScanResult{mDevice=6F:AE:DE:3E:2E:C3, mScanRecord=ScanRecord [mAdvertiseFlags=26, mServiceUuids=[00001805], mManufacturerSpecificData={}, mServiceData={}, mTxPowerLevel=-2147483648, mDeviceName=101-1], mRssi=-81, mTimestampNanos=1043935540628438}
D/RxBle#ClientOperationQueue: QUEUED ConnectOperation(890174706)
D/RxBle#ClientOperationQueue: STARTED ConnectOperation(890174706)
V/RxBle#ConnectOperation: Trying to connectGatt using reflection.
V/RxBle#BleConnectionCompat: Found constructor with args count = 4
V/RxBle#BleConnectionCompat: Connecting using reflection
D/BluetoothGatt: connect() - device: 6F:AE:DE:3E:2E:C3, auto: true
D/BluetoothGatt: registerApp()
D/BluetoothGatt: registerApp() - UUID=125a849aa38e
D/BluetoothGatt: onClientRegistered() - status=0 clientIf=7
D/BluetoothGatt: onClientConnectionState() - status=6 clientIf=7 device=6F:AE:DE:3E:2E:C3
D/RxBle#BluetoothGatt: onConnectionStateChange newState=0 status=6
W/System.err: BleDisconnectedException{bluetoothDeviceAddress='6F:AE:DE:3E:2E:C3'}
W/System.err: at com.polidea.rxandroidble.internal.connection.RxBleGattCallback$2.onConnectionStateChange(RxBleGattCallback.java:76)
W/System.err: at android.bluetooth.BluetoothGatt$1.onClientConnectionState(BluetoothGatt.java:181)
W/System.err: at android.bluetooth.IBluetoothGattCallback$Stub.onTransact(IBluetoothGattCallback.java:70)
W/System.err: at android.os.Binder.execTransact(Binder.java:446)
I/System.out: BleDisconnectedException{bluetoothDeviceAddress='6F:AE:DE:3E:2E:C3'}
I/RxBle#ConnectionOperationQueue: Connection operations queue to be terminated (6F:AE:DE:3E:2E:C3)
D/RxBle#Executors$RunnableAdapter: Terminated.
D/RxBle#ClientOperationQueue: QUEUED DisconnectOperation(550952755)
D/RxBle#ClientOperationQueue: FINISHED ConnectOperation(890174706)
D/RxBle#ClientOperationQueue: STARTED DisconnectOperation(550952755)
D/BluetoothManager: getConnectionState()
D/BluetoothManager: getConnectedDevices
D/BluetoothGatt: close()
D/BluetoothGatt: unregisterApp() - mClientIf=7
D/RxBle#ClientOperationQueue: FINISHED DisconnectOperation(550952755)-
答案 0 :(得分：1)
有多种可能的解决方案可以实现预期的行为，因此操作将在第一次点击Connect按钮时开始，如果在没有用户交互的情况下连接将丢失以重新连接。
你基本上想要的是：
如果由于适配器已关闭而发生断开连接，则首先扫描设备需要解决a bug in Android regarding connecting to a device after BluetoothAdapter being switched on。我们将在这种情况下完成部分流程，并从头开始重复。
Observable<Boolean> canUseBleObservable = canUseBle();
subscription = scanSingleDevice() // first scan the device
.flatMapObservable(this::connectAndDoStuff) // when scanned connect and do your stuff
.takeUntil(canUseBleObservable.takeFirst(isReady -> !isReady)) // if the BLE will be not ready (off) then unsubscribe from scanning and connecting
.delaySubscription(canUseBleObservable.takeFirst(isReady -> isReady)) // delay subscription to scanning and connecting till BLE is ready (subscribing goes from bottom to top)
.retry() // if scan will emit an error (connection should not as it has `.retry()`) just resubscribe to the upstream
.repeatWhen(observable -> observable) // if the upstream will complete (due to `.takeUntil()` as `connectAndDoStuff` does not complete on it's own)—resubscribe to the upstream
.subscribe(
aVoid -> { /* consume */ } // `aVoid` should be changed to your model/events emitted by `.connectAndDoStuff`
// throwable -> { } => should not happen since there is `retry()` in the upstream
);
其他构建块可能如下所示：
private Observable<Boolean> canUseBle() {
return rxBleClient.observeStateChanges()
.share() // share observing state changes
.startWith(Observable.fromCallable(() -> rxBleClient.getState())) // on each subscription emit the current state
.map(state -> state == RxBleClient.State.READY); // map to `true` when ready
}
private Single<RxBleDevice> scanSingleDevice() {
return rxBleClient.scanBleDevices( // scan the device
new ScanSettings.Builder().build(),
new ScanFilter.Builder().setDeviceName("mydevice").build()
)
.map(ScanResult::getBleDevice)
.take(1) // after the first device being scanned stop the scan
.toSingle();
}
private Observable<Void> connectAndDoStuff(RxBleDevice rxBleDevice) {
return rxBleDevice.establishConnection(false)
.flatMap(rxBleConnection -> {
// do your stuff
return Observable.<Void>empty();
})
.repeat(); // if any error (going out of range) will happen then resubscribe from `.establishConnection()`
}
这是对用例的简单分解。如果需要，可以进一步使流程复杂化。