Swift找不到由协议保证的方法

Question

我试图想出一种方法来减少ViewController中使用Cleanse注入依赖的样板代码，然而，我的Cleanse.Component样板绝对停留在我的类型擦除类中。我做错了什么？

(为了便于阅读，包括代码和XCode快照)

import Foundation
import Cleanse

protocol CleanseInjectable {
    func inject(args: Any...) -> Void
    func prepare() -> Void
}

extension CleanseInjectable {
    func inject(args: Any...) -> Void {

    }
}

class AnyCleansePropertyInjectionComponent<TargetType: AnyObject, CleanseInjectable>: Cleanse.Component {
    typealias Root = PropertyInjector<TargetType>

    func configure<B : Binder>(binder binder: B) {
        binder
            .bindPropertyInjectionOf(TargetType.self)
            .to(injector: (TargetType.self as! CleanseInjectable.Type).inject)
    }
}

我得到的错误和任何Swift协议一样离奇--只有在事后才能明显看到的错误：Type 'CleanseInjectable' has no member 'inject'?！

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Answer 1

这个版本似乎修复了这个错误！看起来斯威夫特无法理解TargetType: AnyObject, CleanseInjectable在约束方面等同于protocol CleanseInjectable: class。

import Cleanse

protocol CleanseInjectable: class {
    func inject(args: Any...) -> Void
    func prepare() -> Void
}

extension CleanseInjectable {
    func inject(args: Any...) -> Void {

    }
}

class AnyCleansePropertyInjectionComponent<TargetType: CleanseInjectable>: Cleanse.Component {
    typealias Root = PropertyInjector<TargetType>

    func configure<B : Binder>(binder binder: B) {
        binder
            .bindPropertyInjectionOf(TargetType.self)
            .to(injector: TargetType.inject)
    }
}

编辑:我的已完成的Cleanse样板清除器(未在运行时测试，将尽快更新)，有趣和灵感！

import Cleanse

protocol CleanseInjectable: class {
    var cleanseComponent: AnyCleansePropertyInjectionComponent<Self>? { get }
    func inject(args: Any...) -> Void
    func prepare() -> Void
}

extension CleanseInjectable {
    func inject(args: Any...) -> Void {
        // Override me to do something useful, brah!
    }

    func prepare() -> Void {
        if (cleanseComponent != nil) {
            (try! cleanseComponent!.build()).injectProperties(into: self)
        }
    }
}

class AnyCleansePropertyInjectionComponent<TargetType: CleanseInjectable>: Cleanse.Component {
    typealias Root = PropertyInjector<TargetType>

    func configure<B : Binder>(binder binder: B) {
        binder
            .bindPropertyInjectionOf(TargetType.self)
            .to(injector: TargetType.inject)
    }
}