如何在 swift 4 中解析一个 json 字典，每个字典都包含具有可解码协议的不同键？答案

【问题标题】：How to parse a json dictionary in swift 4 , each containing different keys with decodable protocol?如何在 swift 4 中解析一个 json 字典，每个字典都包含具有可解码协议的不同键？
【发布时间】：2018-09-21 21:55:04
【问题描述】：

我必须解析这个具有不同键的 json 字典。在此示例中，只有 object_summary 键相同，而所有对象中的其他键不同。我想使用带有 JSONDecoder() 的 Swift 4 Decodable 协议来解析它。请帮忙。

     {
           "car": {
              "object_summary": {
                 "type": "consumer product",
                 "name": "ford",
                 "color": "red",
                 "description": "A car is a wheeled motor vehicle used for transportation."
              "doors": "2",
              "price": "$30000",
              "milage": "100 miles"
            },
           "computer": {
              "object_summary": {
                 "type": "hardware",
                 "name": "mac",
                 "color": "silver",
                 "description": "A computer is a device that can be instructed to carry out sequences of arithmetic or s for looms."
              },
              "purchase_date": "March 4, 2018",
              "image": {
                 "url": "https://seniorsnoworlando.org/wp-content/uploads/2014/05/IMG_0009-1038x576.jpg",
                 "width": "50px",
                 "height": "50px"
              }
            },
            "cat": {
              "object_summary": {
                 "type": "animal",
                 "name": "Max",
                 "color": "orange",
                 "description": "The domestic cat carnivorous mammal."
              },
              "age": "2 years",
              "favorite_toy": "ball",
              "image": {
                 "url": "https://www.petful.com/wp-content/uploads/2016/06/american-shorthair-cat-750x434.jpg",
                 "width": "50px",
                 "height": "50px"
              }
            },
            "dog": {
              "object_summary": {
                 "type": "animal",
                 "name": "Jimmy",
                 "color": "black",
                 "description": "The domestic dog."
              "age": "3 years",
              "favorite_toy": "stuff animal",
              "image": {
                 "url": "https://s3.amazonaws.com/cdn-origin-etr.akc.org/wp-content/uploads/2017/11/13000934/Beagle-On-White-08.jpg",
                 "width": "50px",
                 "height": "50px"
              }
            }
        }

我的数据模型如下所示：

 struct DataModel: Codable{

  let objectsummary:ObjectSummary
  let doors,price, milage, purchasedate, age, favoritetoy: String

  private enum CodingKeys: String, CodingKey {case purchasedate = "purchase_date", favoritetoy = "favorite_toy",objectsummary = "object_summary", doors, price, milage,age}

}
struct ObjectSummary:Codable{
  let type: String
  let name: String
  let color: String
  let description: String
}

【问题讨论】：

“car”、“cat”、“dog”键是恒定的还是完全动态的？
它们是不变的。
然后，您可以像使用 ObjectSummary（汽车、猫等）一样简单地构建类（或结构），并拥有一个将这些作为字段包含在内的“根”结构。将该“根”结构发送到解码器。如果出现错误，您可以编辑帖子。
谢谢，我就是这样解决的，而且成功了

标签： ios dictionary swift4 decodable jsondecoder

【解决方案1】：

1：您可以像使用 ObjectSummary 一样构建结构（struct Car、struct Computer 等）。

2：有一个“根”结构，将这些作为字段包含在内。

3：最后，将该“根”结构发送到解码器。

【讨论】：