Question

我正在尝试使用必需的便利性失败的初始化程序。这是我正在使用的代码：

public init(authState: OIDAuthState, config: [String: String], accessibility: CFString = kSecAttrAccessibleWhenUnlockedThisDeviceOnly) throws {
        self.authState = authState
        self.config = config
        self.accessibility = accessibility

        super.init()

        KeycloakAuth.configuration = config
    }

public required convenience init?(coder aDecoder: NSCoder) {
        try? self.init(authState:     aDecoder.decodeObject(forKey: "authState")     as! OIDAuthState,
                       config:        aDecoder.decodeObject(forKey: "config")        as! [String: String],
                       accessibility: aDecoder.decodeObject(forKey: "accessibility") as! CFString)
    }

在'self' used before 'self.init' call行出现错误public required...，在try? self.init(...行再次出现相同的错误。

我已经查看了有关Stack Overflow的其他一些相关问题。即这些：

因此，我相应地安排了方便的初始化，以尝试在出现任何问题时返回nil：

public required convenience init?(coder aDecoder: NSCoder) {
        guard
            let authState     = aDecoder.decodeObject(forKey: "authState")     as? OIDAuthState,
            let config        = aDecoder.decodeObject(forKey: "config")        as? [String: String]
        else {
            print("KeycloakTokenManager: There was an error intializing authState or config")
            return nil
        }

        let accessibility = aDecoder.decodeObject(forKey: "accessibility") as! CFString

        try? self.init(authState: authState, config: config, accessibility: accessibility)
    }

但是我在相同的代码（初始化程序，并调用self.init）上也遇到相同的错误。有趣的是，我的项目在Swift 4上运行良好，但是关于Swift 5的一个错误，我什么都没有听到。我如何摆脱这个错误？

Answer 1

一种解决方案是不调用指定的初始化程序

public required init?(coder aDecoder: NSCoder) {
    guard
        let authState     = aDecoder.decodeObject(forKey: "authState")     as? OIDAuthState,
        let config        = aDecoder.decodeObject(forKey: "config")        as? [String: String]
    else {
        print("KeycloakTokenManager: There was an error intializing authState or config")
        return nil
    }

    self.authState = authState
    self.config = config 
    self.accessibility =  aDecoder.decodeObject(forKey: "accessibility") as! CFString

    super.init()

    KeycloakAuth.configuration = config
}

Answer 2

这是我刚刚发现的另一种解决方案，我认为它比我正在尝试的解决方法更加优雅。因为初始化程序不会抛出，所以最终代码可以像这样：

public init(authState: OIDAuthState, config: [String: String], accessibility: CFString = kSecAttrAccessibleWhenUnlockedThisDeviceOnly) {
    self.authState = authState
    self.config = config
    self.accessibility = accessibility

    super.init()

    KeycloakAuth.configuration = config
}

public required convenience init?(coder aDecoder: NSCoder) {
    self.init(authState:     aDecoder.decodeObject(forKey: "authState")     as! OIDAuthState,
              config:        aDecoder.decodeObject(forKey: "config")        as! [String: String],
              accessibility: aDecoder.decodeObject(forKey: "accessibility") as! CFString)
}

Swift 5：在“ self.init”调用之前使用了“ self”

2 个答案: