Question

我正在尝试进行以下代码编译。基本上我希望对象符合多种协议，例如将不同API组暴露给app的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协议注入此服务，例如实现依赖注入（例如我想传递给LoginController一个采用LoginControllerProvider和FetchingUsersFromDBProvider的注入）：

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()
}

Playground因以下错误而失败：

错误：strings.playground：29：7：错误：输入＆＃39; Injector＆＃39;才不是   遵守协议＆＃39; MyAccountCommunicatorProvider＆＃39;注射器：   MyAccountCommunicatorProvider，EventsCommunicatorProvider {         ^

strings.playground：30：9：注意：候选人有不匹配的类型   ＆＃39;网络管理器＆＃39;       var networkCommunicator：NetworkManager = NetworkManager（）           ^

错误：strings.playground：29：7：错误：输入＆＃39; Injector＆＃39;才不是   符合协议＆＃39; EventsCommunicatorProvider＆＃39;注射器：   MyAccountCommunicatorProvider，EventsCommunicatorProvider {         ^

strings.playground：30：9：注意：候选人有不匹配的类型   ＆＃39;网络管理器＆＃39;       var networkCommunicator：NetworkManager = NetworkManager（）

环境：swift4，XCode9

Answer 1

为什么需要MyAccountCommunicatorProvider和EventsCommunicatorProvider协议？如果将它们组合成一个怎么办？

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

您可以这样使用：

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
    }()
}

Swift协议请求方法返回协议

3 个答案: