swift - SwiftyJson 和 Alamofire 使用的解码结构

Question

如何使用 Alamofire 和 SwiftyJSON 将数据解码为结构？我的尝试给了我这样的错误

"No value associated with key CodingKeys(stringValue: \"user\", intValue: nil)

这是我的代码，当我使用非可选值时，我的尝试没有给我结果，他们用 NIL 值响应我

Alamofire.request(url, method: .post, parameters: params, encoding: URLEncoding.default, headers: nil).responseJSON { (response) in
            if response.data != nil {
                switch response.result {
                case.failure( let error):
                    print(error)
                case.success(let val):
                    var json = JSON(val)
                    print(json)
                    guard let data = response.data else {return}
                    do {
                        let root = try JSONDecoder().decode(MainInfo.self, from: data)
                        print(root.submodel)
                    }
                    catch {
                        print("Bigerror")
                        print(error)
                    }

这是我的结构

struct user: Codable {
    var push_id:String?
    var name:String?
    var id:String?
    var role_id:String?
    var taxi_park_id:Int?
    var car_number:String?

    enum CodingKeys:String,CodingKey {
        case push_id = "push_id"
        case name = "name"
        case id = "id"
        case role_id = "role_id"
        case taxi_park_id = "taxi_park_id"
        case car_number = "car_number"     
    }
}

struct MainInfo : Decodable {
    let model: String?
    let submodel: String?
    let user:user
    enum CodingKeys:String,CodingKey {
        case model = "model"
        case submodel = "submodel"
        case user = "user"

    }
}

这是我打印的漂亮的 json

{
  "facilities" : [

  ],
  "model" : "AMC",
  "taxi_park" : "Taxi +",
  "submodel" : "Gremlin",
  "user" : {
    "role_id" : 2,
    "push_id" : "dW7Cy-ItcDo:APA91bH62zJJKKz0t9VxP29H0iE2xhnQH0hDvKpGaHc5pknuTuZq2lMaj-EapQlN3O4dJF0ysSuCNOeb-2SdJaJaLIZcwHD3CCpeNpz6UVeGktoCm2ykL2rNXF5-ofQckvz1xTvVO0V6",
    "taxi_park_id" : 0,
    "id" : 3,
    "name" : "China",
    "car_number" : "X123OOO"
  }
}

Answer 1

首先，您的问题与 SwiftyJSON 无关，因为您使用的是 Codable。

其次，以大写字母 (User) 命名结构，这样可以避免混淆，例如 let user : user

该错误具有误导性。除了 push_id 之外的所有 .._id 值都是 Int 而不是 String。将字符串与所有其他类型区分开来非常容易:字符串总是用双引号引起来。

如果您通过convertFromSnakeCase key 解码策略，您根本不需要 CodingKeys

struct MainInfo : Decodable {
    let model : String
    let submodel : String
    let user : User
}

struct User: Decodable {
    let pushId : String
    let name : String
    let id : Int
    let roleId : Int
    let taxiParkId : Int
    let carNumber : String
}

...

do {
    let decoder = JSONDecoder()
    decoder.keyDecodingStrategy = .convertFromSnakeCase
    let root = try decoder.decode(MainInfo.self, from: data)
    print(root.submodel)
} catch { print(error) }