ios - 导航堆栈之前的 View 之间的协议(protocol)委托(delegate)

View1 segues到导航控制器-View2 segues到View3
我正在尝试创建从View3到View1的协议委托

在View1中

class NormalUser: UIViewController, NormalUserDelegate {

    @objc func showAddressView() {
        addressView.isHidden = false
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        if let conn = self.storyboard?.instantiateViewController(withIdentifier: "View") as? View
        {
            conn.delegate = self
        }
    }
}

在View3中

weak var delegate: NormalUserDelegate?

func test() {

self.delegate?.showAddressView()

}

协议

protocol NormalUserDelegate: class {
    func showAddressView()
}

我无法使其工作。任何想法？

最佳答案

我的看法是，您有2个不错的选择来使用委托模式。 1个不错的选择将起作用，但它既笨拙又懒惰，然后您具有广播接收器模式。

2个不错的选择

1-向前传递代表

class VC1: UIViewController, SomeDelegate {

    func delegateFunction() {}

    func showNextVC() {
        let next = VC2()
        next.forwardingDelegate = self
        present(next, animated: true)
    }
}

class VC2: UIViewController {
    var forwardingDelegate: SomeDelegate? = nil

    func showNextVC() {
        let next = VC3()
        next.delegate = forwardingDelegate
        present(next, animated: true)
    }
}

2-将第三个控制器传递给第二个控制器

class VC1: UIViewController, SomeDelegate {

    func delegateFunction() {}

    func showNextVC() {
        let final = VC3()
        final.delegate = self

        let next = VC2(withControllerToPresent: final)
        present(next, animated: true)
    }
}

class VC2: UIViewController {
    let controller: UIViewController

    init(withControllerToPresent controller: UIViewController) {
        self.controller = controller
        super.init(withNibName: nil, bundle: nil
    }

    func showNextVC() {
        present(controller, animated: true)
    }
}

class VC3: UIViewController {
    var delegate: SomeDelegate? = nil
}

1个糟糕的选择

使用单例/全局变量...(请不​​要)

个人观点

我已经完成了前两个选项……它们都起作用。但是广播接收器模式可能会更好，因为它会更干净。 VC2不需要将任何内容转发到3。只需确保对通知的命名空间足够具体，以免以后被其他任何内容捕获。