没有与键 CodingKeys 关联的值

Question

我正在尝试解析以下内容 json：

"categories": [
        {
            "id": 42,
            "name": "Air Conditioning",
            "image_url": "system-data/category/Category-AirConditioning.png",
            "image_marker_url": "system-data/category/Marker_Category-Air Conditioning.png",
            "status_id": 7,
            "created_at": 1580452213,
            "updated_at": 1580452213
        },
        {
            "id": 43,
            "name": "Car Wash",
            "image_url": "system-data/category/Category-Carwash.png",
            "image_marker_url": "system-data/category/Marker_Category-Car Wash.png",
            "status_id": 7,
            "created_at": 1580452213,
            "updated_at": 1580452213
        },
        {
            "id": 45,
            "name": "Automobile Services",
            "image_url": "system-data/category/Category-Automobile.png",
            "image_marker_url": "system-data/category/Marker_Category-Automobile Services.png",
            "status_id": 7,
            "created_at": 1580452213,
            "updated_at": 1580452213
        },
        {
            "id": 48,
            "name": "Electrical",
            "image_url": "system-data/category/Category-Electrical.png",
            "image_marker_url": "system-data/category/Marker_Category-Electrical.png",
            "status_id": 7,
            "created_at": 1580452213,
            "updated_at": 1580452213
        },
        {
            "id": 49,
            "name": "Generator Repair & Maintenance",
            "image_url": "system-data/category/Category-Generator.png",
            "image_marker_url": "system-data/category/Marker_Category-Generator Repair & Maintenance.png",
            "status_id": 7,
            "created_at": 1580452213,
            "updated_at": 1580452213
        }
    ]

下面是我将 json 响应映射到模型中的结构：

struct CityCategory: Codable{

    let id: Int
    let name, imageUrl, imageMarkerUrl: String
    let statusID, createdAt, updatedAt: Int

    enum CodingKeys: String, CodingKey{
        case id = "id"
        case name = "name"
        case imageUrl = "image_url"
        case imageMarkerUrl = "image_marker_url"
        case createdAt = "created_at"
        case updatedAt = "updated_at"
        case statusID = "status_id"
    }

}

struct CityCategoryResponse: Codable{
    let cityCat: [CityCategory]
}

我正在尝试这个：

let response = try JSONDecoder().decode(CityCategoryResponse.self, from: jsonData)

它会抛出错误。

keyNotFound(CodingKeys(stringValue: "cityCat", intValue: nil), Swift.DecodingError.Context(codingPath: [], debugDescription: "No value associated with key CodingKeys(stringValue: \"cityCat\", intValue: nil) (\"cityCat\").", underlyingError: nil))

Answer 1

你需要

let categories: [CityCategory]

或

struct CityCategoryResponse: Codable{
    let cityCat: [CityCategory] 

  enum CodingKeys: String, CodingKey{
        case cityCat = "categories" 
    }
}

cityCat isn't a key inside your json , hence the decoder can't find it

没有与键 CodingKeys 关联的值

No value associated with key CodingKeys

parsing

json

swift

codable