CoreBluetooth 外围设备：didDiscoverServices 未触发

Posted 2023-03-05

【中文标题】CoreBluetooth 外围设备：didDiscoverServices 未触发

【英文标题】：CoreBluetooth peripheral:didDiscoverServices not firing

【发布时间】：2017-11-08 08:22:34

【问题描述】：

我有一个简单的应用程序，我在其中实现了一个可以连接到外围设备并对其进行读取或写入的 Central。

由于某些原因，这总是有效的，但现在我不知道为什么委托方法 didDiscoverServices 没有触发。我在 didConnect 方法中调用 peripheral.discoverServices()。当调用 discoverServices 方法时，我不断收到 委托方法未实现或为 nil 的错误。但是方法已经实现了，我正在寻找存在的服务。

这是我的代码

class SearchForPeripheralsTableViewController: UITableViewController, CBCentralManagerDelegate, CBPeripheralDelegate 

var centralManager: CBCentralManager?
var cbPeripheral: CBPeripheral!
var peripherals: [DiscoveryPeripherals] = []

 var listOfServices: [ServiceIdentifier] = []


 fileprivate func fillServices()
        listOfServices.append(ServiceIdentifier(CBUUID(string: "FFF0")))
    

 override func viewWillAppear(_ animated: Bool) 
    tableViewSearchPeripherals.dataSource = self
    tableViewSearchPeripherals.delegate = self

    initCentralManager()


override func viewDidAppear(_ animated: Bool) 
    tableViewSearchPeripherals.reloadData()



override func didReceiveMemoryWarning() 
    super.didReceiveMemoryWarning()


func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) 
    print("Peripheral connected")
    let service = listOfServices.first(where:  $0.uuid == CBUUID(string:"FFF0"))
     peripheral.discoverServices([(service?.uuid)!])


override func viewDidLoad() 
    super.viewDidLoad()
    fillServices()


func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) 
    if error != nil 
        print("Error discovering services: \(String(describing: error?.localizedDescription))")
        return
    

    if let services = peripheral.services 
        for service in services 
            let characteristics = listOfCharacteristics.map( (element) -> CBUUID in return element.uuid)
           //   let characteristic = GetCharacteristicByCBUUID(uuid: CBUUID(string: "FFF1"))
            peripheral.discoverCharacteristics(characteristics, for: service)
        
    

【问题讨论】：

您是否将您的班级设置为外围设备的代表？我在任何地方都看不到。

是的，我做到了。我现在编辑了

在哪里？我还是看不到peripheral.delegate = self 或self.cbPeripheral.delegate = self

天哪，我太笨了。我忘了这样做。谢谢

【参考方案1】：

您必须将您的对象设置为CBPeripheral 的委托，才能调用CBPeripheralDelegate 函数：

func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) 
    print("Peripheral connected")
    peripheral.delegate = self
    let service = listOfServices.first(where:  $0.uuid == CBUUID(string:"FFF0"))
     peripheral.discoverServices([(service?.uuid)!])

【参考方案2】：

斯威夫特 3

func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) 

    peripheral.delegate = self

    self.selectPeripheral.discoverServices(nil)


func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) 

    if let errorService = error

        print(errorService)

        return
       
    else if let services = peripheral.services as [CBService]!

        for service in services

            peripheral.discoverCharacteristics(nil, for: service)
        
    
    print("==>",peripheral.services!)

【参考方案3】：

您还需要初始化 CBCentralManagera 并在 info.plist 中添加“Privacy - Bluetooth Peripheral Usage Description”消息

请检查 Swift 3.0 中的这段代码会对您有所帮助。 https://github.com/JCGuidi/BLE-ios-Swift-3.0/blob/master/Project/BluetoothLE/ViewController.swift