为什么我的 CBPeripheralManager 有广告但无法被发现？

Question

我正在使用我的 iPhone 作为外围设备和我的 mac 作为中心来制作一个核心蓝牙应用程序。我的 iPhone 已开机并有广告，但在蓝牙浏览器中，其他 iPhone 和 Mac 无法发现它。但是，我朋友的安卓手机可以发现它。这是怎么回事？ iOS端：

import UIKit
import CoreBluetooth

class ViewController: UIViewController, CBPeripheralManagerDelegate {

@IBOutlet weak var statusLabel: UILabel!
@IBOutlet weak var connectionInfoLabel: UILabel!
var peripheralManager: CBPeripheralManager!
var accelerometerXCharacteristic: CBMutableCharacteristic!
var phoneDataService: CBMutableService!
var accelerometerXData: Data!

override func viewDidLoad() {
    super.viewDidLoad()

    connectionInfoLabel.isHidden = true
    //Ignore this I was testing the data encoding
    let accelerometerVal = "45"
    let someData = accelerometerVal.data(using: String.Encoding.utf8)
    let revertedString = String(data: someData!, encoding: String.Encoding.utf8)! as String
    let integer = Int(revertedString)!
    print(integer)

    setupBT(delegate: self, intialXData: someData!)
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

func setupBT(delegate: CBPeripheralManagerDelegate, intialXData: Data) {
    peripheralManager = CBPeripheralManager(delegate: delegate, queue: nil)
    //print(peripheralManager.state)

    let accelerometerXCharacteristicUUID = CBUUID(string: "07B24C73-C35B-45C7-A43D-58240E3DB4DF")
    let phoneDataServiceUUID = CBUUID(string: "CAB1B028-2243-4F2C-A2F1-3BE5AD51AD61")

    accelerometerXCharacteristic = CBMutableCharacteristic(type: accelerometerXCharacteristicUUID, properties: CBCharacteristicProperties.read, value: intialXData, permissions: CBAttributePermissions.readable)

    phoneDataService = CBMutableService(type: phoneDataServiceUUID, primary: true)
    phoneDataService.characteristics = [accelerometerXCharacteristic]



}

func peripheralManagerDidUpdateState(_ peripheral: CBPeripheralManager) {
    var statusMessage = ""

    switch peripheral.state {
    case .poweredOn:
        statusMessage = "Bluetooth Status: Turned On"
        peripheralManager.add(phoneDataService)
        peripheralManager.startAdvertising([CBAdvertisementDataServiceUUIDsKey : [phoneDataService.uuid], CBAdvertisementDataLocalNameKey: "DSiPhone"])

    case .poweredOff:
        statusMessage = "Bluetooth Status: Turned Off"

    case .resetting:
        statusMessage = "Bluetooth Status: Resetting"

    case .unauthorized:
        statusMessage = "Bluetooth Status: Not Authorized"

    case .unsupported:
        statusMessage = "Bluetooth Status: Not Supported"

    default:
        statusMessage = "Bluetooth Status: Unknown"
    }

    print(statusMessage)

}

func peripheralManager(_ peripheral: CBPeripheralManager, didAdd service: CBService, error: Error?) {
    if ((error) != nil) {
        print("Error \(error!.localizedDescription)")
    }
}

func peripheralManagerDidStartAdvertising(_ peripheral: CBPeripheralManager, error: Error?) {
    print("Advertising")
    if ((error) != nil) {
        print("Error advertising \(error!.localizedDescription)")
    }
}

func peripheralManager(_ peripheral: CBPeripheralManager, didReceiveRead request: CBATTRequest) {
    var requestedCharacteristic: CBMutableCharacteristic?
    switch request.characteristic.uuid {
    case accelerometerXCharacteristic.uuid:
        requestedCharacteristic = accelerometerXCharacteristic
    default:
        requestedCharacteristic = nil

    }
    if let characteristic = requestedCharacteristic {
        if request.offset > characteristic.value!.count {
            request.value = characteristic.value?.subdata(in: request.offset..<(characteristic.value!.count - request.offset))
            peripheralManager.respond(to: request, withResult: CBATTError.success)
        } else {
            peripheralManager.respond(to: request, withResult: CBATTError.invalidAttributeValueLength)
        }
    } else {
        peripheralManager.respond(to: request, withResult: CBATTError.attributeNotFound)
    }
}

func peripheralManager(_ peripheral: CBPeripheralManager, central: CBCentral, didSubscribeTo characteristic: CBCharacteristic) {
    print("Connection Successful")
    statusLabel.text = "Successful!"
    let didSendValue = peripheralManager.updateValue(accelerometerXData, for: characteristic as! CBMutableCharacteristic, onSubscribedCentrals: nil)
    if !didSendValue {
        print("Send failed")
    }
}
}

正在打印蓝牙状态已打开和广告。在 Mac 端：

import Cocoa
import CoreBluetooth

class ViewController: NSViewController, CBCentralManagerDelegate {
var centralManager: CBCentralManager!
override func viewDidLoad() {
    super.viewDidLoad()
    centralManager = CBCentralManager(delegate: self, queue: nil)

    // Do any additional setup after loading the view.
}

override var representedObject: Any? {
    didSet {
    // Update the view, if already loaded.
    }
}

func setupBT() {

}

func centralManagerDidUpdateState(_ central: CBCentralManager) {
    var statusMessage = ""
    switch central.state {
    case .poweredOn:
        centralManager.scanForPeripherals(withServices: [CBUUID(string: "CAB1B028-2243-4F2C-A2F1-3BE5AD51AD61")], options: nil)
        statusMessage = "Bluetooth Status: Turned On"

    case .poweredOff:
        statusMessage = "Bluetooth Status: Turned Off"

    case .resetting:
        statusMessage = "Bluetooth Status: Resetting"

    case .unauthorized:
        statusMessage = "Bluetooth Status: Not Authorized"

    case .unsupported:
        statusMessage = "Bluetooth Status: Not Supported"

    default:
        statusMessage = "Bluetooth Status: Unknown"
    }

    print(statusMessage)
}

func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
    print("Discovered")
}
}

打印出蓝牙已开启，但没有发现任何东西。

Answer 1

我首选的扫描外围设备的方法是不明确要求任何服务。我发现当CBCentralManager 有时无法从广告本身指示服务时，走这条路线会导致头痛。

相反，发现您感兴趣的外围设备的更可靠方法是不在您的scanForPeripheral 参数中指定任何服务，并且只扫描一次所有内容。在您的 options 字典中包含 CBCentralManagerScanOptionAllowDuplicatesKey 键，其值为 false 包装在 NSNumber 中。

当您收到来自didDiscover peripheral: 方法的回调时，请查看advertisingData。它将有一个名为kCBAdvDataServiceUUIDs 的字段。这将是您放置在外围设备上的一组服务 UUID。检查这些（通常只有一个），看看是否有任何匹配您感兴趣的服务 UUID，如果是，这些是您的外围设备。

---

扫描

注意：通常我会定期执行此操作。

let options: [String: Any] = [CBCentralManagerScanOptionAllowDuplicatesKey: NSNumber(value: false)]
centralManager?.scanForPeripherals(withServices: nil, options: options)

---

回调

func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
    if let ids = advertisementData["kCBAdvDataServiceUUIDs"] as? [CBUUID], 
    let id = ids.first, 
    id == CBUUID(string: "YourServiceID") {
        print("Found Peripheral \(peripheral)")
    }
}

Answer 2

仅供参考，那里的代码在重新启动后工作得很好，所以显然这是核心蓝牙的一个小故障。如果其他人有这个问题，一定要试试这个！