Swift 抛出表达式类型'；错误？'；不符合'；错误'；斯威夫特3

将我的游乐场代码更改为Swift 3，Xcode建议更改

if let requestError = error {
    completion({throw (Error(code: requestError._code, description: requestError.localizedDescription, innerError: nil, informations:nil))})
}

到

但我得到了这个错误：

---

“'Error'不能转换为'Error'；您的意思是使用'as！'强制向下广播吗？”

Swift 3中的错误处理不同。错误现在是您遵守的协议，所以您定义了错误案例，然后抛出

enum NetworkError: Error {
    case unauthorised
    case timeout
    case serverError
    case invalidResponse
}

guard let httpUrlResponse = response as? HTTPURLResponse else {
   throw NetworkError.invalidResponse
}

---

有关更多信息，请参见

如何定义错误类型？

enum NetworkError: Error {
    case unauthorised
    case timeout
    case serverError
    case invalidResponse
}

guard let httpUrlResponse = response as? HTTPURLResponse else {
   throw NetworkError.invalidResponse
}