自定義協議委托為零

Question

我有一個奇怪的錯誤，我的代表為零，不知道在哪里檢查。 也許其他人也有同樣的問題。

我有這個 class 和協議：

protocol NavigationProtocol: class {
    func pushVC()
}

class LocalNotification: NSObject, UNUserNotificationCenterDelegate {

    let notificationCenter = UNUserNotificationCenter.current()
    weak var delegate: NavigationProtocol? {
        didSet {
            print("was set")
        }
    }
.........

    func userNotificationCenter(_ center: UNUserNotificationCenter,
                                didReceive response: UNNotificationResponse,
                                withCompletionHandler completionHandler: @escaping () -> Void) {
        
        self.delegate?.pushVC()
        completionHandler()
    }

在我的 VC 中

class FinalDecisionViewController: UIViewController {

    var localNotification: LocalNotification!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        setupNotification()
    }
    
    private func setupNotification() {
        localNotification = LocalNotification()
        localNotification.delegate = self
        localNotification.scheduleNotification(title: "Loan Approval", message: "Congratulations! Your loan has been approved", type: "Loan Approval")
    }


extension FinalDecisionViewController: NavigationProtocol {
    func pushVC() {
        canMoveToNextVC = true
    }
}
    

觸發計划通知后，我單擊它並調用didReceive並且self.delegate?.pushVC()以某種方式為零，即使已設置委托（已打印來自didSet的消息）。

由於委托為 nil，因此從未觸發擴展中的委托方法。

我還在每個 class 的deinit中打印了一些消息，以查看它是否以某種方式從 memory 中刪除，但它們不是，只有在我從 vc 堆棧中彈出它們之后。

Answer 1

添加

weak var delegate: NavigationProtocol? {
    didSet {
        print("was set")
        notificationCenter.delegate = self
    }
}

或者

localNotification = LocalNotification()
localNotification.delegate = self
localNotification.notificationCenter.delegate = localNotification
localNotification.scheduleNotification(title: "Loan Approval", message: "Congratulations! Your loan has been approved", type: "Loan Approval")