Question

我从服务器获取JSON。对于解析，我使用JASON 图书馆。如何用枚举值解析JSON？

示例：

{
        ...
    "first_name": "John",
    "last_name": "Doe",
    "user_type": "basic"
        ...
}

其中＆＃39; user_type＆＃39;：

enum UserType {
  case basic
  case pro
}

有没有人有任何想法？

Answer 1

如果要在枚举中存储user_type的值：

将您的枚举变量类型更改为字符串：

enum UserType: String {
  case basic = "basic"
  case pro = "pro"
}

解决方案，不使用JASON

将您的JSON存储到字典类型变量中：

let jsonVar = [
    "first_name": "John",
    "last_name": "Doe",
    "user_type": "basic"
] as [String : Any]

现在，从字典变量中获取值并使用原始值创建枚举变量：

if let user_type = jsonVar["user_type"] as? String {
   let usertype = UserType(rawValue: user_type)
}

解决方案，使用JASON

let json = [
    "first_name": "John",
    "last_name": "Doe",
    "user_type": "basic"
] as AnyObject


let jasonVar = JSON(json) 

if let user_type:String = jasonVar["user_type"].string {
   let usertype = UserType(rawValue: user_type)
}

Answer 2

从How to get enum from raw value in Swift?

复制

 enum TestEnum: String {
      case Name = "Name"
      case Gender = "Gender"
      case Birth = "Birth Day"
    }

    let name = TestEnum(rawValue: "Name")!       //Name
    let gender = TestEnum(rawValue: "Gender")!   //Gender
    let birth = TestEnum(rawValue: "Birth Day")! //Birth

Answer 3

如果使用Swift 4，则有一个有用的默认JSONDecoder。举个例子：

import Foundation

let  jsonDict = [
"first_name": "John",
"last_name": "Doe",
"user_type": "basic"
]

let jsonData = try! JSONSerialization.data(withJSONObject: jsonDict, options: [])

enum UserType: String, Codable {
    case basic
    case pro
}

struct User: Codable {
    let firstName : String
    let lastName: String
    let userType: UserType

enum CodingKeys : String, CodingKey {
    case firstName = "first_name"
    case lastName = "last_name"
    case userType = "user_type"
    }
}

let decoder = JSONDecoder()
let user = try! decoder.decode(User.self, from: jsonData)

print(user)

如何使用JASON pod解析枚举？

3 个答案: