在 ios 中未从 BLE 设备获取数据/服务

Question

我需要连接一个 BLE 设备，然后根据其中不同按钮发送的数据处理数据。
为此，我编写了以下代码。

import CoreBluetooth
class HomeViewController: UIViewController,CBPeripheralDelegate,CBCentralManagerDelegate 
{
    var centralManager : CBCentralManager!
    var peri : CBPeripheral!
    override func viewDidLoad()
    {
        super.viewDidLoad()
        centralManager = CBCentralManager(delegate: self, queue: nil)
    }
    func centralManagerDidUpdateState(central: CBCentralManager) {
        if central.state == .Unknown
        {
            print("Unknown")
        }
        else if central.state == .Unsupported
        {
            print("Unsupported")
        }
        else if central.state == .Unauthorized
        {
            print("Unauthorized")
        }
        else if central.state == .Resetting
        {
            print("Resetting")
        }
        else if central.state == .PoweredOn
        {
            print("Powered On")
            startScan()
        }
        else if central.state == .PoweredOff
        {
            print("Powered Off")
        }
    }
    func centralManager(central: CBCentralManager, didDiscoverPeripheral peripheral: CBPeripheral, advertisementData: [String : AnyObject], RSSI: NSNumber) {
        print("Discovered: \(peripheral.name) at \(RSSI)")
        print("AdvertisementData:\(advertisementData)")

        if peri != peripheral
        {
            peri = peripheral
            centralManager.connectPeripheral(peripheral, options: nil)
        }
    }
    func centralManager(central: CBCentralManager, didFailToConnectPeripheral peripheral: CBPeripheral, error: NSError?) {
        print("Failed to connect \(peripheral) cause of \(error)")
    }

    func centralManager(central: CBCentralManager, didConnectPeripheral peripheral: CBPeripheral) {
        print("connected to \(peripheral)")
//        centralManager.stopScan()
        print("Available services:\(peripheral.services)")
    }
    func peripheral(peripheral: CBPeripheral, didDiscoverIncludedServicesForService service: CBService, error: NSError?) {
        print("Services\(service) and error\(error)")
    }
    func peripheral(peripheral: CBPeripheral, didDiscoverServices error: NSError?) {
        print("Services and error\(error)")
    }
    func startScan(){
        print("Scanning...")
        centralManager.scanForPeripheralsWithServices(nil, options: nil)
    }
}

这是我的代码日志。

Powered On
Scanning...
Discovered: Optional("**** BLE") at 127
AdvertisementData:["kCBAdvDataIsConnectable": 1, "kCBAdvDataServiceUUIDs": (
    1802
)]
connected to <CBPeripheral: 0x12756d910, identifier = 6197****-EB0A-F1E8-BEF4-1AFAC629C5BC, name = **** BLE, state = connected>
Available services:nil

这是从 BLE 设备单击一个按钮时生成的输出。但是当我点击另一个按钮时，我无法接收或读取数据。
Android 同一应用的开发者已经集成了这两个按钮。
所以设备没有任何问题。
任何人都可以帮助我指导我在这段代码中出错的地方吗？？

Answer 1

连接到外围设备后，您必须使用要发现的服务的 UUID 在外围设备上调用 discoverServices，然后您必须发现服务的特征。如果您希望在单击按钮时进行更新，则必须为与该按钮对应的特征打开通知

如果您仍然需要帮助，我强烈推荐 link 来自 apple 的这篇文章作为后续阅读。它以比我在这里描述的更好的方式描述了您需要逐步完成的操作。

Apple BLE Guide

Answer 2

您还必须在连接到设备后发现服务和特征。

例如，在您的 "didConnectPeripheral" 方法中，您必须执行如下操作：

 func centralManager(central: CBCentralManager, didConnectPeripheral peripheral: CBPeripheral) {
    print("connected to \(peripheral)")
    peripheral.delegate = self
    peripheral.discoverServices(nil)
    print("Discovering services!")
}

然后：

func peripheral(peripheral: CBPeripheral, didDiscoverServices error: NSError?) {
    print("Discovered services: \(peripheral.services), Error\(error)")
    if let services = peripheral.services {
        for service in services {
            peripheral.discoverCharacteristics(nil, forService: service)
        }
    }
}

然后你必须处理每个特征：

 func peripheral(peripheral: CBPeripheral, didDiscoverCharacteristicsForService service: CBService, error: NSError)

您必须记住手动存储每个特征，否则它们将被释放。

为了接收流数据（通知），您必须为每个特征启用通知。

peripheral.setNotifyValue(true, forCharacteristic: characteristic)

您还必须实施：

 func peripheral(peripheral: CBPeripheral, didUpdateValueForCharacteristic characteristic: CBCharacteristic, error: NSError)

处理传入值的顺序。

如您所见，开始需要大量样板代码。

Answer 3

Pandafox 的回答很完美，只是缺少一件事。
这是外设的设置委托。

这是发现外围设备、连接到它并发现其服务和特征的完整代码。

1.Connect外设

func centralManager(central: CBCentralManager, didDiscoverPeripheral peripheral: CBPeripheral, advertisementData: [String : AnyObject], RSSI: NSNumber) {
    print("Discovered: \(peripheral.name) at \(RSSI)")
    print("AdvertisementData:\(advertisementData)")

    if peri != peripheral
    {
        peri = peripheral
        peri.delegate = self
        centralManager.connectPeripheral(peri, options: nil)
    }
}

连接失败或成功

func centralManager(central: CBCentralManager, didFailToConnectPeripheral peripheral: CBPeripheral, error: NSError?) {
    print("Failed to connect \(peripheral) cause of \(error)")
}

func centralManager(central: CBCentralManager, didConnectPeripheral peripheral: CBPeripheral) {
    print("connected to \(peripheral)")
//        centralManager.stopScan()
    peripheral.discoverServices(nil)
}

3.DiscoverServices

func peripheral(peripheral: CBPeripheral, didDiscoverServices error: NSError?) {
        print("Services:\(peripheral.services) and error\(error)")
        if let services = peripheral.services {
            for service in services {
                peripheral.discoverCharacteristics(nil, forService: service)
            }
        }
    }

发现特征并设置通知

func peripheral(peripheral: CBPeripheral, didDiscoverCharacteristicsForService service: CBService, error: NSError?)
    {
        print("peripheral:\(peripheral) and service:\(service)")
        for characteristic in service.characteristics!
        {
            peripheral.setNotifyValue(true, forCharacteristic: characteristic)
        }
    }

处理更新特征值的通知

func peripheral(peripheral: CBPeripheral, didUpdateValueForCharacteristic characteristic: CBCharacteristic, error: NSError?)
    {
        print("characteristic changed:\(characteristic)")
    }

在 ios 中未从 BLE 设备获取数据/服务

not getting data / services from BLE device in ios

ios

core-bluetooth

bluetooth-lowenergy

swift