首页 > 解决方案 > 无法从枚举中获取原始字符串

问题描述

我在 URLSession 类上有以下扩展名:

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 Errors 的这些结构和枚举:

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"
}

最后是我对登录 Web 服务的调用:

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)
        }
    }

事情是我想获取代表我的枚举的字符串以显示正确的错误消息,但我完全可以访问这个值。如果我尝试对错误进行本地化描述,我会得到一个完全不同的字符串,其中包含以下内容:"The operation could not be completed"

标签: swifterror-handlingenums

解决方案


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

请试试这个:

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
    }
}

推荐阅读