Swift，iOS：如何从混凝土类型中获得多态性和脱致协调员

Question

我有以下协议：

protocol Coordinator {
    var rootViewController: UIViewController { get set }
    func start()
}

protocol UIViewControllerFactory {
    func mainViewController() -> UIViewController
}

我创建了一个符合此协议的Main Coordinator ，并且通过了一个工厂，该工厂使我可以将协调器解脱出来，无法创建和捕获混凝土类型，因此可以是 polymormormorphic < /strong>，可以与 uiviewController的更多实现一起使用， rootviewControllers 和 mainmenuviewController ，如下所示：

class MainCoordinator: Coordinator {
    var rootViewController: UIViewController
    let factory: UIViewControllerFactory 
    
    init(rootViewController: UIViewController, factory: UIViewControllerFactory) {
        self.rootViewController = rootViewController
    }
    
    start() {
        guard let mainVC = factory.mainViewController() as? MainViewController, let rootViewController = rootViewController as? UINavigationViewController  else { return }
        
        mainVC.delegate = self
        rootViewController.push(mainVC, animated: true)
    }

尽管我可以看到，但VE创建了协调器，以接受UiviewController的任何子类，它已在 start 函数中耦合到UiviewController的具体实现：MainViewController。

我如何将其从mainviewController中解脱出来，并使它更多态？

Answer 1

您可以将协调器作为出厂函数中的参数类型传递，并在创建Controller实例时直接在出厂功能中进行委托。这样，您就不必将Controller type显式地从工厂类中出现。

我想到了以下方法。

protocol Coordinator {
    var rootViewController: UIViewController { get set }
    func start()
}

protocol UIViewControllerFactory {
    func getViewController(delegateType:CoordinatoreTypes,delegateObject:Coordinator) -> UIViewController?
}

class MainCoordinator: Coordinator {
    var rootViewController: UIViewController
    let factory: UIViewControllerFactory
    
    init(rootViewController: UIViewController, factory: UIViewControllerFactory) {
        self.rootViewController = rootViewController
        self.factory = factory
    }
    
    func start() {
        guard let controller = factory.getViewController(delegateType: .MainCoordinator, delegateObject: self),let rootViewController = rootViewController as? UINavigationViewController else {
            return
        }
        rootViewController.push(mainVC, animated: true)
    }
}

extension MainCoordinator:DelegateCaller{
    func printHello() {
        print("helloo")
    }
}

enum CoordinatoreTypes{
    case MainCoordinator
    case none
}

class Factory:UIViewControllerFactory{
    func getViewController(delegateType:CoordinatoreTypes,delegateObject:Coordinator) -> UIViewController?{
        switch delegateType{
        case .MainCoordinator:
            let controller = MainViewController()
            controller.delegate = delegateObject as? MainCoordinator
            return controller
        case .none:
            break
        }
        return nil
    }
}

class MainViewController:UIViewController{
    weak var delegate:DelegateCaller?
}

protocol DelegateCaller:AnyObject{
    func printHello()
}