Question

所以我遇到了一个非常棘手的问题。我的JSON代码有一个很奇怪的结构。它具有以下结构：

{
    "title": [
        [
            "Temperature",
            "9 \u00b0C (283 \u00b0F)",
            "Good"
        ],
        [
            "Visibility",
            "10 KM (6.2 Mi)",
            "Good"
        ]
    ]
}

使用以下代码，我可以打印出一些简单的json代码：

import UIKit

struct WeatherItem: Decodable {
    let title: String?
    let value: String?
    let condition: String?
}

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()

        let jsonUrlString = "http://somelinkhere"
        guard let url = URL(string: jsonUrlString) else { return }

        URLSession.shared.dataTask(with: url) { (data, response, err) in
            guard let data = data else { return }

            do {
                let weather = try JSONDecoder().decode(WeatherItem.self, from: data)
                print(weather.title)
            } catch let jsonErr{
                print("error", jsonErr)
            }
        }.resume()
    }
}

但是问题是我对所有3个变量（标题，值和条件nil）的输出都是。我确定必须更改结构代码，但是我不知道该怎么做。

如何获取无标题的JSON代码？

Answer 1

更正json

{
    "title": [
        [
            "Temperature",
            " ",
            "Good"
        ],
        [
            "Visibility",
            "10 KM (6.2 Mi)",
            "Good"
        ]
    ]

}

var arr = [WeatherItem]()
do {
     let res = try JSONDecoder().decode([String:[[String]]].self, from: data)
     let content = res["title"]!
     content.forEach {
       if $0.count >= 3 {
         arr.append(WeatherItem(title:$0[0],value:$0[1],condition:$0[2]))
       }
     }
     print(arr)
} catch {
  print(error)
}

讨论：您的根对象是一个字典，其中包含一个名为title的键，其值是一个字符串数组数组，或者从模型逻辑中它是一个名为{ {1}}，但结构不正确，因此使用

WeatherItem

不起作用，因为当前json不包含键let weather = try JSONDecoder().decode(WeatherItem.self, from: data)和value

合适的结构是

condition

这将使您能够做到

[
    {
        "title":"Temperature" ,
        "value":"",
        "condition":"Good"
    },
    {
        "title":"Visibility",
        "title":"10 KM (6.2 Mi)",
        "condition":"Good"
    }
]

Answer 2

您将必须自己编写解码初始化程序：

struct WeatherData: Decodable {
    let title: [WeatherItem]
}

struct WeatherItem: Decodable {
    let title: String?
    let value: String?
    let condition: String?

    public init(from decoder: Decoder) throws {
        // decode the value for WeatherItem as [String]         
        let container = try decoder.singleValueContainer()
        let components = try container.decode([String].self)

        title = components.count > 0 ? components[0] : nil
        value = components.count > 1 ? components[1] : nil
        condition = components.count > 2 ? components[2] : nil
    }
}

let json = """
{
  "title": [
     ["Temperature", "9", "Good"],
     ["Visibility", "10 KM (6.2 Mi)", "Good"]
   ]
}
"""

let jsonData: Data = json.data(using: .utf8)!
let decoder = JSONDecoder()

let decoded = try! decoder.decode(WeatherData.self, from: jsonData)
debugPrint(decoded)

迅速的json解析，没有json对象的标题

2 个答案: