swift - 如何声明泛型基类？

Question

我有一个案例是:

class BaseMvpController<V, P: BasePresenter>: UIViewController { }

我需要将基类设为通用类型而不是 UIViewController .

在某些时候，我需要它是 UIViewController , UITableViewController ..等等

例如:

我的基类

class BaseMvpController<V, P: BasePresenter>: UIViewController  {
    typealias View = V
    private(set) var presenter: P!
    // MARK: - Initializers

    required public init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }

    override public init(nibName: String?, bundle: Bundle?) {
        super.init(nibName: nibName, bundle: bundle)
    }

    deinit {
        guard let view = self as? P.View else {return}
        if let presenter = presenter {
            presenter.detachView(view)
        }
    }


    // MARK: - Lifecycle

    override func viewDidLoad() {
        super.viewDidLoad()
        presenter = createPresenter()
    }

    override func viewWillAppear(_ animated: Bool) {
        guard let view = self as? P.View else {
            preconditionFailure("MVP ViewController must implement the view protocol `\(View.self)`!")
        }

        super.viewWillAppear(animated)

        if !presenter.isAttached {
            presenter.attachView(view)
        }
    }
    // MARK: - MVP

    /// Override and return a presenter in a subclass.
    func createPresenter() -> P {
        preconditionFailure("MVP method `createPresenter()` must be override in a subclass and do not call `super.createPresenter()`!")
    }

}

我的AController

class AController : BaseMvpController <AView, APresenter> { }

If we thought it was a kind of UIViewController its works normally

我的BController

class BController : BaseMvpController <AView, APresenter> { }

If we thought it was a kind of UITableViewController, This is case I can not override numberOfItemInRaw and dequeCell ...etc , because base controller inherit from UIViewController

我想让 Base Controller 与所有 Controller ( UIViewController 、 UITableViewController 、 UICollectionViewController .. 等)一起工作。

我该怎么做

Answer 1

您可以将泛型“隐藏”在另一个类中。

例如，

class Generic<T, U> { }
class BV: UIViewController {
    var generic: Generic<Int, String>? = nil
}