在Swift中迭代解码JSON的字典键

在上一个问题中，我得到了非常好的帮助，关于如何建立我的基础JSON模型。我可以解析任何我想要的值

虽然我可以解析我想要的任何值，但我只能使用点符号分别访问符号或其他值。

btcSymbol=rawResponse.btc？.symbol

ethSymbol=rawResponse.eth？.symbol

我还发现了关于迭代字典的其他问题，例如，但这些示例是基本数组，而不是使用Swift新协议的多嵌套字典

我希望能够：
1.迭代JSON并从CMC API中仅提取符号。
2.有一个模型，我可以分别迭代每种货币的所有值，以便稍后将这些值发送到表视图中。

BTC | name | symbol | marketCap | MaxSupply

ETH | name | symbol | marketCap | MaxSupply

重组我已经存在的模型是最好的解决方案吗？在我的模型建立之后，在循环或映射中使用标准会更好吗

JSONModel

struct RawServerResponse : Codable {
enum Keys : String, CodingKey {
    case data = "data"
}
let data : [String:Base]
}

struct Base : Codable {
enum CodingKeys : String, CodingKey {
    case id = "id"
    case name = "name"
    case symbol = "symbol"
}

let id : Int64
let name : String
let symbol : String
}

struct Quote : Codable {
enum CodingKeys : String, CodingKey {
    case price = "price"
    case marketCap = "market_cap"
}

let price :  Double
let marketCap : Double
}

extension RawServerResponse {
enum BaseKeys : String {
    case btc = "1"
    case eth = "1027"      
}
var btc : Base? { return data[BaseKeys.btc.rawValue] }
var eth : Base? { return data[BaseKeys.eth.rawValue] }

}

extension Base {
enum Currencies : String {
    case usd = "USD"
}
var usd : Quote? { return quotes[Currencies.usd.rawValue]}
}

struct ServerResponse: Codable {
let btcName: String?
let btcSymbol: String?

init(from decoder: Decoder) throws {
    let rawResponse = try RawServerResponse(from: decoder)

    btcSymbol = rawResponse.btc?.symbol

JSON

---

至少我建议映射

数据

字典，以获取

符号

作为键，而不是

id

，顺便说一句，如果键是可计算的，并且您通过

。例如，convertFromSnakeCase

键解码策略，您不需要任何编码键

struct RawServerResponse : Codable {
    var data = [String:Base]()

    private enum CodingKeys: String, CodingKey { case data }

    init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        let baseDictionary = try container.decode([String:Base].self, forKey: .data)
        baseDictionary.forEach { data[$0.1.symbol] = $0.1 }
    }
}

struct Base : Codable {
    let id : Int64
    let name : String
    let symbol : String
    let quotes : [String:Quote]
}

struct Quote : Codable {
    let price : Double
    let marketCap : Double
}

do {
    let decoder = JSONDecoder()
    decoder.keyDecodingStrategy = .convertFromSnakeCase
    let rawResponse = try decoder.decode(RawServerResponse.self, from: data)
    for (symbol, base) in rawResponse.data {
        print(symbol, base.quotes["USD"]?.marketCap)
        // ETH Optional(68660795252.0)
        // BTC Optional(139991426153.0)
    }
} catch { print(error) }

struct RawServerResponse : Codable {
    var data = [String:Base]()

    private enum CodingKeys: String, CodingKey { case data }

    init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        let baseDictionary = try container.decode([String:Base].self, forKey: .data)
        baseDictionary.forEach { data[$0.1.symbol] = $0.1 }
    }
}

struct Base : Codable {
    let id : Int64
    let name : String
    let symbol : String
    let quotes : [String:Quote]
}

struct Quote : Codable {
    let price : Double
    let marketCap : Double
}

do {
    let decoder = JSONDecoder()
    decoder.keyDecodingStrategy = .convertFromSnakeCase
    let rawResponse = try decoder.decode(RawServerResponse.self, from: data)
    for (symbol, base) in rawResponse.data {
        print(symbol, base.quotes["USD"]?.marketCap)
        // ETH Optional(68660795252.0)
        // BTC Optional(139991426153.0)
    }
} catch { print(error) }