无法从枚举中获取原始字符串

时间:2019-11-13 12:31:32

标签: swift error-handling enums

我对URLSession类具有以下扩展名:

extension URLSession {

    @discardableResult
    func sendRequest<A>(endpoint: Endpoint<A>, onComplete: @escaping (Result<A?, Error>) -> ()) -> URLSessionDataTask {
        let task = dataTask(with: endpoint.request, completionHandler: { data, response, err in
            if let err = err {
                onComplete(.failure(err))
              return
            }
            if let da = data, let a = try? JSONDecoder().decode(APIError.self, from: da) {
                if a.error.message == "The username or password is wrong" {
                    onComplete(.failure(LoginErrors.uOrPincorrect))
                }
                if a.error.message == "Your account is locked" {
                    onComplete(.failure(LoginErrors.accountLocked))
                }
                return
            }
        task.resume()
        return task
    }
}

然后是这些错误的结构和枚举:

struct APIError: Decodable {
    let error: APIErrorMessage
}

struct APIErrorMessage: Decodable {
    let message: String
}


enum LoginErrors: String, Error {
    case uOrPincorrect = "The username or password you entered is/are wrong"
    case accountLocked = "Account Locked"
    case unknownError = "Unknown error"
}

最后我打电话给登录Web服务:

func sessionCall(_ res: Result<LoginResponseData?, Error>) {
        switch res {
        case .success(let response):
                ...... // Some code
        case .failure(let error):
                self.showLoginError(error: //HOW TO GET THE STRING FROM ERROR HERE)
        }
    }

我想获取代表我的枚举的字符串以显示正确的错误消息,但是我完全可以访问该值。如果我尝试使用错误的 localizedDescription ,则会得到一个完全不同的字符串,其内容如下:“操作无法完成”。

1 个答案:

答案 0 :(得分:2)

如果您想使用localizedDescription从包括您在内的所有错误中获取错误消息,则您的自定义错误类型需要符合LocalizedError

请尝试以下操作:

enum LoginErrors: String, LocalizedError {
    case uOrPincorrect = "The username or password you entered is/are wrong"
    case accountLocked = "Account Locked"
    case unknownError = "Unknown error"

    var errorDescription: String? {
        self.rawValue
    }
}