CoreBluetooth 功能在 Singleton 中不起作用

Question

所以我目前在 iPad 和 iPhone 之间设置了蓝牙连接。我在ViewController 中创建了我的测试代码，一切正常。现在，我将其移至 2 个管理器类，一个用于 CBCentralManager，一个用于 CBPeripheralManager，上面我创建了一个 BluetoothManager 的类，这是一个单例类，包含有关当前连接设备的一些信息。

但是，当我这样做时，我遇到了一个问题，似乎centralManager.connect() 调用实际上不起作用。我调试了我的整个代码，在那一行之后似乎什么都没有发生，我似乎无法弄清楚为什么会这样或者我实际上哪里出错了。

CentralManager 类

import Foundation
import CoreBluetooth

class CentralManager: NSObject {
    private var centralManager: CBCentralManager!
    var peripherals: [CBPeripheral] = []

    override init() {
        super.init()

        centralManager = CBCentralManager(delegate: self, queue: DispatchQueue.main)
    }
}

// MARK: - CBCentralManager Delegate Methods
extension CentralManager: CBCentralManagerDelegate {

    func centralManagerDidUpdateState(_ central: CBCentralManager) {
        switch central.state {
        case .poweredOn:
            centralManager.scanForPeripherals(withServices: [BLEConstants.serviceUUID], options: [CBCentralManagerScanOptionAllowDuplicatesKey: true])
        default:
            break
        }
    }

    func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
        if !peripherals.contains(peripheral) {
            peripheral.delegate = self
            peripherals.append(peripheral)
            centralManager.connect(peripheral, options: nil)
        }
    }

    func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) {
        peripheral.discoverServices([BLEConstants.serviceUUID])
    }

    func centralManager(_ central: CBCentralManager, didDisconnectPeripheral peripheral: CBPeripheral, error: Error?) {
        guard let peripheralIndex = peripherals.index(of: peripheral), BluetoothManager.shared.deviceCharacteristic[peripheral] != nil else { return }

        peripherals.remove(at: peripheralIndex)
        BluetoothManager.shared.deviceCharacteristic.removeValue(forKey: peripheral)
    }

}

// MARK: - CBPeripheral Delegate Methods
extension CentralManager: CBPeripheralDelegate {

    func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) {
        for service in peripheral.services! {
            if service.uuid == BLEConstants.serviceUUID {
                peripheral.discoverCharacteristics(nil, for: service)
            }
        }
    }

    func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
        for characteristic in service.characteristics! {
            let characteristic = characteristic as CBCharacteristic

            if BluetoothManager.shared.deviceCharacteristic[peripheral] == nil {
                BluetoothManager.shared.deviceCharacteristic[peripheral] = characteristic
            }
        }
    }

    func peripheral(_ peripheral: CBPeripheral, didModifyServices invalidatedServices: [CBService]) {

    }

}

PeripheralManager 类

class PeripheralManager: NSObject {
    private var peripheralManager: CBPeripheralManager!

    override init() {
        super.init()

        peripheralManager = CBPeripheralManager(delegate: self, queue: nil)
    }

}

// MARK: - Manage Methods
extension PeripheralManager {

    func updateAdvertising() {
        guard !peripheralManager.isAdvertising else { peripheralManager.stopAdvertising(); return }

        let advertisingData: [String: Any] = [CBAdvertisementDataServiceUUIDsKey: BLEConstants.serviceUUID,
                               CBAdvertisementDataLocalNameKey: BLEConstants.bleAdvertisementKey]
        peripheralManager.startAdvertising(advertisingData)
    }

    func initializeService() {
        let service = CBMutableService(type: BLEConstants.serviceUUID, primary: true)

        let characteristic = CBMutableCharacteristic(type: BLEConstants.charUUID, properties: BLEConstants.charProperties, value: nil, permissions: BLEConstants.charPermissions)
        service.characteristics = [characteristic]

        peripheralManager.add(service)
    }

}

// MARK: - CBPeripheralManager Delegate Methods
extension PeripheralManager: CBPeripheralManagerDelegate {

    func peripheralManagerDidUpdateState(_ peripheral: CBPeripheralManager) {
        if peripheral.state == .poweredOn {
            initializeService()
            updateAdvertising()
        }
    }

    func peripheralManager(_ peripheral: CBPeripheralManager, didReceiveWrite requests: [CBATTRequest]) {
        for request in requests {
            if let value = request.value {
                let messageText = String(data: value, encoding: String.Encoding.utf8)
                print(messageText ?? "")
            }
            self.peripheralManager.respond(to: request, withResult: .success)
        }
    }

}

BluetoothManager 类

class BluetoothManager {
    static let shared = BluetoothManager()
    private var centralManager: CentralManager!
    private var peripheralManager: PeripheralManager!

    var deviceCharacteristic: [CBPeripheral: CBCharacteristic] = [:]
    var connectedPeripherals: [CBPeripheral] { return centralManager.peripherals }

    func setup() {
        centralManager = CentralManager()
        peripheralManager = PeripheralManager()
    }

}

然后在我的ViewController didLoad 我打电话给BluetoothManager.shared.setup()

有谁知道为什么这些设备似乎没有相互连接，或者之后的委托函数没有被调用？

Answer 1

当静态shared 变量使用BluetoothManager() 初始化时，该过程开始。我不确定这在 Swift 中什么时候发生，要么是在程序的一开始，要么是在你第一次使用 BluetoothManager.setup 时。 变量的初始化调用BluetoothManager 的init() 方法。这将实例化一个CentralManager，并调用它的init() 方法。这将实例化一个CBCentralManager，它将启动蓝牙进程。

然后调用setup()，它将实例化一个新的CentralManager，并带有自己的CBCentralManager。我可以想象两个CBCentralManager 有问题。

要解决它，不要使用setup()，而是初始化init()中的变量。

要调试这种情况，请在所有init() 方法中设置断点。创建析构函数，并在其中放置断点。从技术上讲，无论如何您都需要析构函数，因为您需要从 CBCentralManager 对象中删除自己作为委托。

---

另请注意，您只能从centralManagerDidUpdateState 调用scanForPeripherals。 CBCentralManager 在启动时可能已经处于 poweredOn 状态，这可能发生在另一个应用程序同时使用蓝牙时 - 或者当您的第一个 CBCentralManager 对象已经启动它时。在这种情况下，centralManagerDidUpdateState 将永远不会被调用。

Answer 2

您确定您的单例已正确初始化吗？

试试这个：

import Foundation

private let singleton = Singleton()

class Singleton {

  static let sharedInstance : Singleton = {
    return singleton
  }()

  let cnetralManager = = CBCentralManager(delegate: self, queue: DispatchQueue.main)
}