Swift协议重构方法返回协议

Question

我正在努力使下面的代码编译。基本上，我希望有符合多个协议的对象，例如，将不同组API暴露给应用程序不同部分的网络服务(例如:登录API到loginController，共享API到shareController)。

+

我希望使用networkXProvider协议注入该服务，例如实现依赖注入(例如，我希望将采用LoginControllerProvider和FetchingUsersFromDBProvider的注入传递给LoginController )：

protocol MyAccountCommunicator {
    func getAccountData() -> String
}

protocol EventsCommunicator {
    func getEvents() -> String
}


 class NetworkManager: MyAccountCommunicator, EventsCommunicator {
    func getAccountData() -> String {
        return "Accounts"
    }

    func getEvents() -> String {
        return "Events"
    }
}

protocol MyAccountCommunicatorProvider {
    var networkCommunicator: MyAccountCommunicator { get }
}


protocol EventsCommunicatorProvider {
    var networkCommunicator: EventsCommunicator { get }
}

class Injector: MyAccountCommunicatorProvider, EventsCommunicatorProvider {
    var networkCommunicator: NetworkManager = NetworkManager()
}

操场发生故障，错误如下：

错误: strings.playground:29:7:错误:类型'Injector‘不符合协议'MyAccountCommunicatorProvider’类喷射器: MyAccountCommunicatorProvider，EventsCommunicatorProvider {^ strings.playground:30:9:注意:候选人具有非匹配类型' NetworkManager‘var networkCommunicator: NetworkManager= NetworkManager() ^ 错误: strings.playground:29:7:错误:类型'Injector‘不符合协议' EventsCommunicatorProvider’类喷射器: MyAccountCommunicatorProvider，EventsCommunicatorProvider{^ strings.playground:30:9:注意:候选人具有非匹配类型' NetworkManager‘var networkCommunicator: NetworkManager= NetworkManager()

环境: swift4，XCode9

Answer 1

为什么需要MyAccountCommunicatorProvider和EventsCommunicatorProvider协议？如果你把它们组合成一个呢？

protocol CommunicatorProvider {
 var networkCommunicator: NetworkManager { get }
}

class Injector: CommunicatorProvider {
   var networkCommunicator = NetworkManager()
}

Answer 2

    protocol MyAccountCommunicator {
    func getAccountData() -> String
}

protocol EventsCommunicator {
    func getEvents() -> String
}

protocol MyAccountCommunicatorProvider {
    var accountCommunicator: MyAccountCommunicator { get }
}

protocol EventsCommunicatorProvider {
    var eventCommunicator: EventsCommunicator { get }
}

class NetworkManager: MyAccountCommunicator, EventsCommunicator {
    func getAccountData() -> String {
        return "Accounts"
    }

    func getEvents() -> String {
        return "Events"
    }
}

class Injector: MyAccountCommunicatorProvider, EventsCommunicatorProvider {
    var networkManager = NetworkManager()
    var accountCommunicator: MyAccountCommunicator {
        return networkManager
    }

    var eventCommunicator: EventsCommunicator {
        return networkManager
    }
}

Answer 3

你可以这样使用：

protocol MyAccountCommunicatorProvider {
    var networkCommunicator1: MyAccountCommunicator { get }
}

protocol EventsCommunicatorProvider {
    var networkCommunicator2: EventsCommunicator { get }
}

class Injector: MyAccountCommunicatorProvider, EventsCommunicatorProvider {
    var networkCommunicator: NetworkManager = NetworkManager()
    lazy var networkCommunicator1: MyAccountCommunicator = {
        return networkCommunicator
    }()
    lazy var networkCommunicator2: EventsCommunicator = {
        return networkCommunicator
    }()
}