Question

我已将CoreBluetooth设置在我的应用程序中作为Central，实现了CBCentralManagerDelegate以使用我的服务扫描外围设备。我还在bluetooth-central文件中声明了Info.plist后台模式。

连接后，我会发现服务并阅读我需要的任何特征。当在外围设备侧修改或添加服务时，我会响应外围设备：didModifyServices：方法，并重新发现服务，这在前台工作正常。

我的问题是，当我的应用程序在后台，并且我连接的外围设备添加服务时，不会调用外围设备：didModifyServices：方法。但是，当我的Central应用程序在后台时，不会调用该方法。当我的应用程序在后台时，会收到其他CBPeripheralDelegate方法（外围设备：didDiscoverServices：，外围设备：didDiscoverCharacteristicsForService：错误：等）。

此行为对bluetooth-central后台模式是否正确？代码如下：

CBCentralManagerDelegate：

func centralManagerDidUpdateState(_ central: CBCentralManager) {
    if central.state == .poweredOn {
        central.scanForPeripherals(withServices: [primaryService], options: nil)
    }
}

func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
    if let name = advertisementData[CBAdvertisementDataLocalNameKey] as? String {
        print("Discovered peripheral " + name)
        peripheral.delegate = self
        connectedPeripherals.insert(peripheral)
        central.connect(peripheral, options: nil)
    }
}

func centralManager(_ central: CBCentralManager, didDisconnectPeripheral peripheral: CBPeripheral, error: Error?) {
    connectedPeripherals.remove(peripheral)
}

func centralManager(_ central: CBCentralManager, didFailToConnect peripheral: CBPeripheral, error: Error?) {
    connectedPeripherals.remove(peripheral)
}

func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) {
    peripheral.discoverServices(nil)
}

CBPeripheralDelegate：

func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) {
    for service in peripheral.services ?? [] {
        if isRecognizedService(service) {
            peripheral.discoverCharacteristics(nil, for: service)
        }
    }
}

func peripheral(_ peripheral: CBPeripheral, didModifyServices invalidatedServices: [CBService]) {
    print("Peripheral services changed...")
    peripheral.discoverServices(nil)
}

func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
    guard error == nil else {
        print("Error discovering characteristics...")
        return
    }

    guard let characteristics = service.characteristics, !characteristics.isEmpty else {
        print("No characteristics found for service...")
        return
    }

    for characteristic in service.characteristics ?? [] {
        // Subscribe to characteristic changes, etc...
    }
}

peripheral：didModifyServices（）没有在后台调用？

0 个答案: