如何在swift中正确读取ble外围值？

import CoreBluetooth

class BLEManager: NSObject, CBCentralManagerDelegate, CBPeripheralDelegate {
    var centralManager: CBCentralManager!
    var peripheral: CBPeripheral!
    
    override init() {
        super.init()
        
        centralManager = CBCentralManager(delegate: self, queue: nil)
    }
    
    func centralManagerDidUpdateState(_ central: CBCentralManager) {
        if central.state == .poweredOn {
            centralManager.scanForPeripherals(withServices: nil, options: nil)
        }
    }
    
    func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
        // 这里可以根据外围设备的名称或其他标识符来判断是否连接到目标设备
        if peripheral.name == "YourPeripheralDeviceName" {
            self.peripheral = peripheral
            centralManager.connect(peripheral, options: nil)
        }
    }
    
    func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) {
        peripheral.delegate = self
        peripheral.discoverServices(nil)
    }
    
    func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) {
        if let services = peripheral.services {
            for service in services {
                peripheral.discoverCharacteristics(nil, for: service)
            }
        }
    }
    
    func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
        if let characteristics = service.characteristics {
            for characteristic in characteristics {
                if characteristic.properties.contains(.read) {
                    peripheral.readValue(for: characteristic)
                }
            }
        }
    }
    
    func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {
        if let value = characteristic.value {
            // 在这里处理特征的值
            print("Characteristic value: \(value)")
        }
    }
}