Swift iOS：如何从 BLE 外设获取服务

如何解决Swift iOS：如何从 BLE 外设获取服务

我正在使用 SwiftUI 构建一个 iOS 应用程序。我是 iOS Swift 开发的初学者。我的应用程序需要连接到 BLE 设备并从中获取服务。另外，从中获取数据。但它不起作用。

我有一个名为 BLEManager 的类，代码如下。

import Foundation
import CoreBluetooth

class BleManager: NSObject,ObservableObject,CBCentralManagerDelegate,CBPeripheralDelegate {
    @Published var peripherals = [ BleDevice ]()
    @Published var services = [ BleService ]()
    @Published var characteristies = [ CBCharacteristic ]()
    @Published var isSwitchedOn = false
    var myCentral: CBCentralManager!
    var connectedPeripheral: CBPeripheral!
    
    override init() {
        super.init()
        myCentral = CBCentralManager(delegate: self,queue: nil)
        myCentral.delegate = self
    }
    
    func centralManagerDidUpdateState(_ central: CBCentralManager) {
        if central.state == .poweredOn {
            isSwitchedOn = true
        } else {
            isSwitchedOn = false
        }
    }
    
    func centralManager(_ central: CBCentralManager,diddiscover peripheral: CBPeripheral,advertisementData: [String : Any],RSSi RSSI: NSNumber) {
        var peripheralName: String!
        
        if let name = advertisementData[CBAdvertisementDataLocalNameKey] as? String {
            peripheralName = name
        } else {
            peripheralName = "UnkNown"
        }
        
        let newPeripheral = BleDevice(id: peripherals.count,name: peripheralName,RSSi: RSSI.intValue,peripheral: peripheral)
        peripherals.append(newPeripheral)
    }
    
    func peripheral(_ peripheral: CBPeripheral,didUpdateValueFor characteristic: CBCharacteristic,error: Error?) {
        //Todo
    }
    
    func peripheral(_ peripheral: CBPeripheral,diddiscoverServices error: Error?) {
        guard let localServices = peripheral.services else {
                return
            }
        
        var newServices = [BleService]()
        var id = 1
        for service in localServices {
            newServices.append(BleService(
                                id: id,uuid: service.uuid.uuidString,peripheral: peripheral,service: service
            ))
            id = id + 1
        }
        
        services = newServices
    }
    
    func startScanning() {
        myCentral.scanForperipherals(withServices: nil,options: nil)
    }
    
    func stopScanning() {
        myCentral.stopScan()
    }
    
    func connect(peripheral: CBPeripheral) {
        myCentral.connect(peripheral,options: nil)
        connectedPeripheral = peripheral
        connectedPeripheral.delegate = self
    }
    
    func disconnect(peripheral: CBPeripheral) {
        myCentral.cancelPeripheralConnection(peripheral)
    }
    
    func discoverServices() {
        connectedPeripheral.discoverServices(nil)
    }
    
    func discovercharacteristics(service: CBService) {
        //Todo
    }
    
    func discovercharacteristics(peripheral: CBPeripheral,service: CBService) {
        //Todo
    }
}

我有一个 ContentView 可以扫描 BLE 设备并使用以下代码列出它们。

struct ContentView: View {
    @Observedobject var bleManager = BleManager()
    init() {
    }
    
    var body: some View {
        NavigationView {
            vstack() {
                if bleManager.isSwitchedOn {
                    Text("Bluetooth is switched on")
                        .foregroundColor(.green)
                }
                else {
                    Text("Bluetooth is NOT switched on")
                        .foregroundColor(.red)
                }
                List(bleManager.peripherals){
                    peripheral in vstack {
                        Text(String(peripheral.id))
                        Text(peripheral.name)
                        NavigationLink(destination: ServicesListView(device: peripheral)) {
                            Text("Connect")
                                .padding()
                                .foregroundColor(/*@START_MENU_TOKEN@*/.blue/*@END_MENU_TOKEN@*/)
                            Spacer()
                        }
                        Spacer()
                }.navigationTitle("Devices")
                }
                Spacer()
                Button("Scan Devies") {
                    self.bleManager.startScanning()
                }
                Spacer()
                Button("Stop Scanning") {
                    self.bleManager.stopScanning()
                }
            }
        }
        .padding()
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

然后我有列出连接的设备/外围设备的服务的 ServicesListView。

struct ServicesListView: View {
    @Observedobject var bleManager = BleManager()
    var device: BleDevice
    
    var body: some View {
        vstack {
            Button("Connect and get services") {
                bleManager.connect(peripheral: device.peripheral)
                bleManager.discoverServices()
            }
            Spacer()
            Button("disconnect") {
                bleManager.disconnect(peripheral: device.peripheral)
            }
            Spacer()
            Text(device.name)
            Spacer()
            List(bleManager.services) {
                service in vstack {
                    Text(String(service.id))
                    Text(service.uuid)
                }
            }
        }
    }
}

struct ServicesListView_Previews: PreviewProvider {
    static var previews: some View {
        ServicesListView(device: BleDevice(id:  123,name: "test",RSSi: 123,peripheral: nil))
    }
}

当我单击“连接并获取服务”按钮时，它没有列出所连接外围设备的服务。我的代码有什么问题？