如何使用 URLSession 从 HTTP 请求的 JSON 对象中获取特定属性

Question

通过以下代码，我能够有效地获取 JSON 对象，但我不确定如何从对象中检索特定属性。

Swift代码

@IBAction func testing(_ sender: Any) {
    let url = URL(string: "http://example.com/cars/mustang")

    let task = URLSession.shared.dataTask(with: url!) { data, response, error in
        guard error == nil else {
            print(error!)
            return
        }
        guard let data = data else {
            print("Data is empty")
            return
        }
        let json = try! JSONSerialization.jsonObject(with: data, options: [])
        print(json)
    }
    task.resume()
}

这是我在运行上面的代码时看到的...

输出 - JSON 对象

(
    {
    color = "red";
    engine = "5.0";
    }
)

我怎样才能得到属性颜色？

谢谢

Answer 1

创建一个确认可解码协议的class；例如您的 CarInfo

class CarInfo: Decodable

创建 class

的属性

var color: String

var engine: String

创建 JSON 继承自 CodingKey

的密钥枚举

enum CarInfoCodingKey: String, CodingKey {
   case color 
   case engine 
}

执行初始化

required init(from decoder: Decoder) throws

class 将是

class CarInfo: Decodable {
var color: String
var engine: String
enum CarInfoCodingKey: String, CodingKey {
case color
case engine
}
public init(from decoder: Decodabler) throws {
let container = try decoder.container(keyedBy: CarInfoCodingKey.self)
self.color = try container.decode(String.self, forKey: .color)
self.engine = try contaire.decode(String.self, forKey: .engine)
}
}

调用解码器

let carinfo = try JsonDecoder().decode(CarInfo.self, from: jsonData)

Answer 2

这是我的做法...

@IBAction func testing(_ sender: Any) {
    let url = URL(string: "http://example.com/cars/mustang")

    let task = URLSession.shared.dataTask(with: url!) { data, response, error in
        guard error == nil else {
            print(error!)
            return
        }
        guard let data = data else {
            print("Data is empty")
            return
        }
        let json = try! JSONSerialization.jsonObject(with: data, options: [])

        guard let jsonArray = json as? [[String: String]] else {
            return
        }
        let mustangColor = jsonArray[0]["color"]

        print(mustangColor!)
    }
    task.resume()
}

如何使用 URLSession 从 HTTP 请求的 JSON 对象中获取特定属性

How to get specific properties from a JSON object from HTTP request using URLSession

swift

nsurlsession

Swift代码

输出 - JSON 对象