如何在iOS应用程序中检测USB线连接？

import ExternalAccessory

class ViewController: UIViewController, EAAccessoryDelegate, EAAccessoryManagerDelegate {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        EAAccessoryManager.shared().registerForLocalNotifications()
        NotificationCenter.default.addObserver(self, selector: #selector(accessoryConnected), name: NSNotification.Name.EAAccessoryDidConnect, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(accessoryDisconnected), name: NSNotification.Name.EAAccessoryDidDisconnect, object: nil)
    }
    
    @objc func accessoryConnected(notification: NSNotification) {
        if let accessory = notification.userInfo?[EAAccessoryKey] as? EAAccessory {
            // USB accessory connected
            print("USB accessory connected: \(accessory.name)")
        }
    }
    
    @objc func accessoryDisconnected(notification: NSNotification) {
        if let accessory = notification.userInfo?[EAAccessoryKey] as? EAAccessory {
            // USB accessory disconnected
            print("USB accessory disconnected: \(accessory.name)")
        }
    }
}