Swift 4 用变量作为键解析 json [重复]

我试图了解苹果添加的新 Codable 功能，但我无法解决这个问题。 我有一个 json 输出，如下所示

{
    "Afpak": {
        "id": 1,
        "race": "hybrid",
        "flavors": [
            "Earthy",
            "Chemical",
            "Pine"
        ],
        "effects": {
            "positive": [
                "Relaxed",
                "Hungry",
                "Happy",
                "Sleepy"
            ],
            "negative": [
                "Dizzy"
            ],
            "medical": [
                "Depression",
                "Insomnia",
                "Pain",
                "Stress",
                "Lack of Appetite"
            ]
        }
    }
}

我有一个类似的结构

struct Strain: Codable {
    var name: String
    var id: Int
    var race: String
    var flavors: [String]
    var effects: [String: [String]]

}

很明显它会失败，因为我的 json 中没有名称键。名称应该是“Afpak”，我环顾四周，但大多数教程没有给出任何关于如何解决这个问题的示例，他们只是这样做[String:Strain]这不是我需要的。无论如何，是否将我的字典的键设置为我的名称变量？

只需将您的 name 属性设置为可选，为您的结构创建一个自定义初始化程序，该结构采用字典并使用其第一个键来初始化您的 name 属性：

enum ParseError: Error {
    case noKeyFound
}
struct Strain: Codable {
    let name: String!
    let id: Int
    let race: String
    let flavors: [String]
    let effects: [String: [String]]
    init(dictionary: [String: Strain]) throws {
        guard
            let key = dictionary.keys.first,
            let strain = dictionary[key] else { throw ParseError.noKeyFound }
        name = key
        id = strain.id
        race = strain.race
        flavors = strain.flavors
        effects = strain.effects
    }
}

do {
    let strain = try Strain(dictionary: JSONDecoder().decode([String:Strain].self, from: data))
    print(strain) // Strain(name: Afpak, id: 1, race: "hybrid", flavors: ["Earthy", "Chemical", "Pine"], effects: ["positive": ["Relaxed", "Hungry", "Happy", "Sleepy"], "negative": ["Dizzy"], "medical": ["Depression", "Insomnia", "Pain", "Stress", "Lack of Appetite"]])
} catch {
    print(error)
}