使用结构在 Swift 5 中使用 JSON 解码器解析 JSON

Question

我从 Rest API 中得到 json 格式的结果。现在我想用 JSON 解码器解析这个 JSON 但我并不真正理解我的响应的结构。

为此，我已经尝试创建结构来获取 "FirstUser" 的 "name"。

{  
   "User":[  
      {  
         "FirstUser":{  
            "name":"John"
         },
         "Information":"XY",
         "SecondUser":{  
            "name":"Tom"
         }

Answer 1

Json

{
    "User":[
      {
        "FirstUser":{
        "name":"John"
        },
       "Information":"XY",
        "SecondUser":{
        "name":"Tom"
      }
     }
   ]
}

型号

// MARK: - Empty
struct Root: Codable {
    let user: [User]

    enum CodingKeys: String, CodingKey {
        case user = "User"
    }
}

// MARK: - User
struct User: Codable {
    let firstUser: FirstUserClass
    let information: String
    let secondUser: FirstUserClass

    enum CodingKeys: String, CodingKey {
        case firstUser = "FirstUser"
        case information = "Information"
        case secondUser = "SecondUser"
    }
}

// MARK: - FirstUserClass
struct FirstUserClass: Codable {
    let name: String
}

解析

do {
    let res = try JSONDecoder().decode(Root.self, from: data) 
    print(res.first?.firstUser.name)
} catch {
    print(error)
}

Answer 2

如果我使用以前的 json 创建模型使用此 link [博客]：http://www.jsoncafe.com 生成 Codable 结构或任何格式

型号

import Foundation
struct RootClass : Codable {
    let user : [Users]?
    enum CodingKeys: String, CodingKey {
        case user = "User"
    }

    init(from decoder: Decoder) throws {
        let values = try? decoder.container(keyedBy: CodingKeys.self)
        user = try? values?.decodeIfPresent([Users].self, forKey: .user)
    }
}

struct Users : Codable {
    let firstUser : FirstUser?
    let information : String?
    let secondUser : SecondUser?
    enum CodingKeys: String, CodingKey {
        case firstUser = "FirstUser"
        case information = "Information"
        case secondUser = "SecondUser"
    }
    init(from decoder: Decoder) throws {
        let values = try? decoder.container(keyedBy: CodingKeys.self)
        firstUser = try? FirstUser(from: decoder)
        information = try? values?.decodeIfPresent(String.self, forKey: .information)
        secondUser = try? SecondUser(from: decoder)
    }
}
struct SecondUser : Codable {
    let name : String?
    enum CodingKeys: String, CodingKey {
        case name = "name"
    }
    init(from decoder: Decoder) throws {
        let values = try? decoder.container(keyedBy: CodingKeys.self)
        name = try? values?.decodeIfPresent(String.self, forKey: .name)
    }
}
struct FirstUser : Codable {
    let name : String?
    enum CodingKeys: String, CodingKey {
        case name = "name"
    }
    init(from decoder: Decoder) throws {
        let values = try? decoder.container(keyedBy: CodingKeys.self)
        name = try? values?.decodeIfPresent(String.self, forKey: .name)
    }
}

解析

    do {
        let res = try JSONDecoder().decode(RootClass.self, from: data)
        print(res?.user?.first?.firstUser?.name ?? "Yours optional value")
    } catch {
        print(error)
    }

使用结构在 Swift 5 中使用 JSON 解码器解析 JSON

Parse JSON with JSONDecoder in Swift 5 using structs

ios

json

swift

parsing

jsondecoder