swift 可编码 :Nested Dictionary not being read

Question

我得到了一些像这样的 json(这是伪造的，并不是所有的键都在这里):

{
    "absolute_magnitude_h" = "23.4";
    ...
    "close_approach_data" = (
                {
            "close_approach_date" = "1994-09-03";
            "epoch_date_close_approach" = 778575600000;
            "orbiting_body" = Earth;
}

我有一个具有这个结构的对象:

struct NEOObj:Codable {

    var absoluteMagnitudeH:Float
    var designation:String
    var isPotentiallyHazardousAsteroid:Bool
    var isSentryObject:Bool
    var name:String
    var nasaJPLURL:String
    var neoReferenceID:String
    var closeApproachData:[NEOCloseApproachData] = [NEOCloseApproachData]()

    private enum CodingKeys: String, CodingKey {
        case absoluteMagnitudeH = "absolute_magnitude_h"
        case designation = "designation"
        case isPotentiallyHazardousAsteroid = "is_potentially_hazardous_asteroid"
        case isSentryObject = "is_sentry_object"
        case name = "name"
        case nasaJPLURL = "nasa_jpl_url"
        case neoReferenceID = "neo_reference_id"
    }

enum CloseApproachCodingKeys: String, CodingKey {
        case closeApproachDate = "close_approach_date"
        case epochDateCloseApproach = "epoch_date_close_approach"
        case orbitingBody = "orbiting_body"
    }

struct NEOCloseApproachData:Codable {

    var closeApproachDate:Date
    var epochDateCloseApproach:Date
    var orbitingBody:String

    enum CodingKeys: String, CodingKey {
        case closeApproachDate = "close_approach_date"
        case epochDateCloseApproach = "epoch_date_close_approach"
        case orbitingBody = "orbiting_body"
    }
}

在我的文件中我有这段代码:

if let arrNEOs = dictJSON["near_earth_objects"] as? Array<Any> {

    for thisNEODict in arrNEOs {

     do {
         let jsonData = try JSONSerialization.data(withJSONObject: thisNEODict, options: .prettyPrinted)
         let thisNEOObj = try? JSONDecoder().decode(NEOObj.self, from: jsonData)
         print(thisNEOObj!.closeApproachData)
     } catch {

     }
    }

   }

但是 closeApproachData 永远不会被填充。我做错了什么？

Answer 1

要使其正常工作，需要更改多项内容。

---

closeApproachData 应该是 [NEOCloseApproachData] 类型。您没有在代码中包含 CloseApproachCodingKeys，但它可能不正确。

---

NEOObj.CodingKeys 需要有一个 closeApproachData 的案例，看起来像

case closeApproachData = "close_approach_data"

---

NEOCloseApproachData 需要一个自定义解码器来处理 closeApproachDate 和 epochDateCloseApproach 的日期。由于 JSON 具有不同的格式(分别为 String 和 Int)，您不能在 JSONDecoder.dateDecodingStrategy 上使用，因为它将应用于所有日期。