swift - 如何使用类型为 "Cannot invoke ' 的参数列表修复 '(eventStore: EventStoring)' createEvent'

Question

我正在使用 EventKit 的 EKEventStore，我想模拟它和 EKEvent。但是我不知道如何正确抽象EKEvent's init(eventStore: EKEventStore) 和其他方法。

protocol EventStoring {

    associated type Event: EventStoreEvent where Event.MatchingEventStore == Self

    func save(_ event: Event, span: EKSpan, commit: Bool) throws

    // Other methods of EKEventStore I use
 }

extension EKEventStore: EventStoring {
    typealias Event = EKEvent
}

protocol EventStoreEvent {
    associatedtype MatchingEventStore: EventStoring

    static func createEvent(eventStore: MatchingEventStore) -> Self
}

extension EKEvent: EventStoreEvent {
    typealias MatchingEventStore = EKEventStore

    static func createEvent(eventStore: MatchingEventStore) -> Self {
        return EKEvent(eventStore: eventStore) as! Self 
    }
}

此处的错误是:“'Self' 仅在协议(protocol)中可用或作为类中方法的结果可用；您是说 'EKEvent' 吗？”并且:“无法将类型 'EKEvent' 的返回表达式转换为返回类型'Self'”

class GenericEventManger<StoreEvent: EventStoreEvent> {

    var store: EventStoring

    required init(with eventStore: EventStoring) {
        self.store = eventStore
    }

    func createEvent() -> StoreEvent {
        let eventStoreEvent: EventStoreEvent = StoreEvent.createEvent(eventStore: store)

    // Then some code where I configure the event...

    try store.save(eventStoreEvent, span: .thisEvent, commit: true)
    }
}

在倒数第七行，错误是:无法使用 '(eventStore: EventStoring)' 类型的参数列表调用 'createEvent'在倒数第三个是:无法使用 '(StoreEvent, span: EKSpan, commit: Bool)' 类型的参数列表调用 'save'

更新 由于我采纳了 Dan 的建议，在我的实现过程中出现了另一个同类问题，所以我更新了我的问题

Answer 1

我想在 Dan 的帮助下，到目前为止我已经找到了两个问题的解决方案，但我还没有彻底测试它:

首先，我按照 Dan 的建议更改了 GenericStoreManager 的 store 属性的类型

class GenericStoreManger<StoreEvent: EventStoreEvent> {

    var store: StoreEvent.MatchingEventStore

    func createEvent() -> StoreEvent {
    let eventStoreEvent: EventStoreEvent = StoreEvent.createEvent(eventStore: store)

    // Then some code where I configure the event...

    try store.save(eventStoreEvent as! StoreEvent.MatchingEventStore.Event, span: .thisEvent, commit: true)
}

    ...

}

然后我更改了在 extension EKEvent: EventStoreEvent 中获取返回值的方式，因此它也可以在 EKEvent 的子类中工作

extension EKEvent: EventStoreEvent {
    typealias MatchingEventStore = EKEventStore

    static func createEvent(eventStore: MatchingEventStore) -> Self {
        return self.init(eventStore: eventStore) 
    }
}