如何在 Swift [45] 可解码协议中解码具有 JSON 字典类型的属性

Question

假设我有 Customer 数据类型，其中包含一个 metadata 属性，它可以包含客户对象中的任何 JSON 字典

struct Customer {
  let id: String
  let email: String
  let metadata: [String: Any]
}

{  
  "object": "customer",
  "id": "4yq6txdpfadhbaqnwp3",
  "email": "john.doe@example.com",
  "metadata": {
    "link_id": "linked-id",
    "buy_count": 4
  }
}

metadata属性可以是任意的JSON地图对象。

在我可以从 NSJSONDeserialization 的反序列化 JSON 转换属性之前，但是使用新的 Swift 4 Decodable 协议，我仍然可以'想不出办法。

有人知道如何使用可解码协议在 Swift 4 中实现这个吗？

Answer 1

您可以创建确认 Decodable 协议的元数据结构，并使用 JSONDecoder class 通过使用如下解码方法从数据创建对象

let json: [String: Any] = [
    "object": "customer",
    "id": "4yq6txdpfadhbaqnwp3",
    "email": "john.doe@example.com",
    "metadata": [
        "link_id": "linked-id",
        "buy_count": 4
    ]
]

struct Customer: Decodable {
    let object: String
    let id: String
    let email: String
    let metadata: Metadata
}

struct Metadata: Decodable {
    let link_id: String
    let buy_count: Int
}

let data = try JSONSerialization.data(withJSONObject: json, options: .prettyPrinted)

let decoder = JSONDecoder()
do {
    let customer = try decoder.decode(Customer.self, from: data)
    print(customer)
} catch {
    print(error.localizedDescription)
}

Answer 2

当我找到旧答案时，我只测试了一个简单的 JSON 对象案例，但没有测试一个空的案例，它会导致运行时异常，如找到@slurmomatic 和@zoul。很抱歉这个问题。

所以我尝试了另一种方法，通过一个简单的 JSONValue 协议，实现 AnyJSONValue 类型擦除结构并使用该类型而不是 Any。这是一个实现。

public protocol JSONType: Decodable {
    var jsonValue: Any { get }
}

extension Int: JSONType {
    public var jsonValue: Any { return self }
}
extension String: JSONType {
    public var jsonValue: Any { return self }
}
extension Double: JSONType {
    public var jsonValue: Any { return self }
}
extension Bool: JSONType {
    public var jsonValue: Any { return self }
}

public struct AnyJSONType: JSONType {
    public let jsonValue: Any

    public init(from decoder: Decoder) throws {
        let container = try decoder.singleValueContainer()

        if let intValue = try? container.decode(Int.self) {
            jsonValue = intValue
        } else if let stringValue = try? container.decode(String.self) {
            jsonValue = stringValue
        } else if let boolValue = try? container.decode(Bool.self) {
            jsonValue = boolValue
        } else if let doubleValue = try? container.decode(Double.self) {
            jsonValue = doubleValue
        } else if let doubleValue = try? container.decode(Array<AnyJSONType>.self) {
            jsonValue = doubleValue
        } else if let doubleValue = try? container.decode(Dictionary<String, AnyJSONType>.self) {
            jsonValue = doubleValue
        } else {
            throw DecodingError.typeMismatch(JSONType.self, DecodingError.Context(codingPath: decoder.codingPath, debugDescription: "Unsupported JSON tyep"))
        }
    }
}

下面是解码时的使用方法

metadata = try container.decode ([String: AnyJSONValue].self, forKey: .metadata)

这个问题的问题是我们必须调用value.jsonValue as? Int。我们需要等到 Conditional Conformance 登陆 Swift，这将解决这个问题或至少帮助它变得更好。

[旧答案]

我在 Apple Developer 论坛上 post 这个问题，结果很简单。

我可以

metadata = try container.decode ([String: Any].self, forKey: .metadata)

在初始化程序中。

首先错过它是我的遗憾。

Answer 3

从 this gist I found, I wrote some extensions for UnkeyedDecodingContainer and KeyedDecodingContainer. You can find a link to my gist here 中得到一些启发。通过使用此代码，您现在可以使用熟悉的语法解码任何 Array<Any> 或 Dictionary<String, Any>：

let dictionary: [String: Any] = try container.decode([String: Any].self, forKey: key)

或

let array: [Any] = try container.decode([Any].self, forKey: key)

编辑： 我发现一个警告，它正在解码一组字典 [[String: Any]] 所需的语法如下。您可能希望抛出错误而不是强制转换：

let items: [[String: Any]] = try container.decode(Array<Any>.self, forKey: .items) as! [[String: Any]]

编辑 2: 如果您只想将整个文件转换为字典，最好坚持使用 JSONSerialization 中的 api，因为我还没有弄清楚一种扩展 JSONDecoder 本身以直接解码字典的方法。

guard let json = try JSONSerialization.jsonObject(with: data, options: []) as? [String: Any] else {
  // appropriate error handling
  return
}

扩展

// Inspired by https://gist.github.com/mbuchetics/c9bc6c22033014aa0c550d3b4324411a

struct JSONCodingKeys: CodingKey {
    var stringValue: String

    init?(stringValue: String) {
        self.stringValue = stringValue
    }

    var intValue: Int?

    init?(intValue: Int) {
        self.init(stringValue: "\(intValue)")
        self.intValue = intValue
    }
}


extension KeyedDecodingContainer {

    func decode(_ type: Dictionary<String, Any>.Type, forKey key: K) throws -> Dictionary<String, Any> {
        let container = try self.nestedContainer(keyedBy: JSONCodingKeys.self, forKey: key)
        return try container.decode(type)
    }

    func decodeIfPresent(_ type: Dictionary<String, Any>.Type, forKey key: K) throws -> Dictionary<String, Any>? {
        guard contains(key) else { 
            return nil
        }
        guard try decodeNil(forKey: key) == false else { 
            return nil 
        }
        return try decode(type, forKey: key)
    }

    func decode(_ type: Array<Any>.Type, forKey key: K) throws -> Array<Any> {
        var container = try self.nestedUnkeyedContainer(forKey: key)
        return try container.decode(type)
    }

    func decodeIfPresent(_ type: Array<Any>.Type, forKey key: K) throws -> Array<Any>? {
        guard contains(key) else {
            return nil
        }
        guard try decodeNil(forKey: key) == false else { 
            return nil 
        }
        return try decode(type, forKey: key)
    }

    func decode(_ type: Dictionary<String, Any>.Type) throws -> Dictionary<String, Any> {
        var dictionary = Dictionary<String, Any>()

        for key in allKeys {
            if let boolValue = try? decode(Bool.self, forKey: key) {
                dictionary[key.stringValue] = boolValue
            } else if let stringValue = try? decode(String.self, forKey: key) {
                dictionary[key.stringValue] = stringValue
            } else if let intValue = try? decode(Int.self, forKey: key) {
                dictionary[key.stringValue] = intValue
            } else if let doubleValue = try? decode(Double.self, forKey: key) {
                dictionary[key.stringValue] = doubleValue
            } else if let nestedDictionary = try? decode(Dictionary<String, Any>.self, forKey: key) {
                dictionary[key.stringValue] = nestedDictionary
            } else if let nestedArray = try? decode(Array<Any>.self, forKey: key) {
                dictionary[key.stringValue] = nestedArray
            }
        }
        return dictionary
    }
}

extension UnkeyedDecodingContainer {

    mutating func decode(_ type: Array<Any>.Type) throws -> Array<Any> {
        var array: [Any] = []
        while isAtEnd == false {
            // See if the current value in the JSON array is `null` first and prevent infite recursion with nested arrays.
            if try decodeNil() {
                continue
            } else if let value = try? decode(Bool.self) {
                array.append(value)
            } else if let value = try? decode(Double.self) {
                array.append(value)
            } else if let value = try? decode(String.self) {
                array.append(value)
            } else if let nestedDictionary = try? decode(Dictionary<String, Any>.self) {
                array.append(nestedDictionary)
            } else if let nestedArray = try? decode(Array<Any>.self) {
                array.append(nestedArray)
            }
        }
        return array
    }

    mutating func decode(_ type: Dictionary<String, Any>.Type) throws -> Dictionary<String, Any> {

        let nestedContainer = try self.nestedContainer(keyedBy: JSONCodingKeys.self)
        return try nestedContainer.decode(type)
    }
}

Answer 4

这个问题我也玩过，最后写了一个simple library for working with “generic JSON” types。（其中“泛型”的意思是“没有预先知道的结构”。）要点是用具体类型表示泛型 JSON：

public enum JSON {
    case string(String)
    case number(Float)
    case object([String:JSON])
    case array([JSON])
    case bool(Bool)
    case null
}

此类型可以实现 Codable 和 Equatable。

Answer 5

你可以看看BeyovaJSON

import BeyovaJSON

struct Customer: Codable {
  let id: String
  let email: String
  let metadata: JToken
}

//create a customer instance

customer.metadata = ["link_id": "linked-id","buy_count": 4]

let encoder = JSONEncoder()
encoder.outputFormatting = .prettyPrinted 
print(String(bytes: try! encoder.encode(customer), encoding: .utf8)!)

Answer 6

这是受@loudmouth 回答启发的更通用（不仅[String: Any]，而且[Any] 可以解码）和封装的方法（为此使用单独的实体）。

使用它看起来像：

extension Customer: Decodable {
  public init(from decoder: Decoder) throws {
    let selfContainer = try decoder.container(keyedBy: CodingKeys.self)
    id = try selfContainer.decode(.id)
    email = try selfContainer.decode(.email)
    let metadataContainer: JsonContainer = try selfContainer.decode(.metadata)
    guard let metadata = metadataContainer.value as? [String: Any] else {
      let context = DecodingError.Context(codingPath: [CodingKeys.metadata], debugDescription: "Expected '[String: Any]' for 'metadata' key")
      throw DecodingError.typeMismatch([String: Any].self, context)
    }
    self.metadata = metadata
  }

  private enum CodingKeys: String, CodingKey {
    case id, email, metadata
  }
}

JsonContainer 是我们用来将解码 JSON 数据包装到 JSON 对象（数组或字典）而不扩展 *DecodingContainer 的辅助实体（所以它不会'当 JSON 对象不是 [String: Any]) 时，不会干扰极少数情况。

struct JsonContainer {

  let value: Any
}

extension JsonContainer: Decodable {

  public init(from decoder: Decoder) throws {
    if let keyedContainer = try? decoder.container(keyedBy: Key.self) {
      var dictionary = [String: Any]()
      for key in keyedContainer.allKeys {
        if let value = try? keyedContainer.decode(Bool.self, forKey: key) {
          // Wrapping numeric and boolean types in `NSNumber` is important, so `as? Int64` or `as? Float` casts will work
          dictionary[key.stringValue] = NSNumber(value: value)
        } else if let value = try? keyedContainer.decode(Int64.self, forKey: key) {
          dictionary[key.stringValue] = NSNumber(value: value)
        } else if let value = try? keyedContainer.decode(Double.self, forKey: key) {
          dictionary[key.stringValue] = NSNumber(value: value)
        } else if let value = try? keyedContainer.decode(String.self, forKey: key) {
          dictionary[key.stringValue] = value
        } else if (try? keyedContainer.decodeNil(forKey: key)) ?? false {
          // NOP
        } else if let value = try? keyedContainer.decode(JsonContainer.self, forKey: key) {
          dictionary[key.stringValue] = value.value
        } else {
          throw DecodingError.dataCorruptedError(forKey: key, in: keyedContainer, debugDescription: "Unexpected value for \(key.stringValue) key")
        }
      }
      value = dictionary
    } else if var unkeyedContainer = try? decoder.unkeyedContainer() {
      var array = [Any]()
      while !unkeyedContainer.isAtEnd {
        let container = try unkeyedContainer.decode(JsonContainer.self)
        array.append(container.value)
      }
      value = array
    } else if let singleValueContainer = try? decoder.singleValueContainer() {
      if let value = try? singleValueContainer.decode(Bool.self) {
        self.value = NSNumber(value: value)
      } else if let value = try? singleValueContainer.decode(Int64.self) {
        self.value = NSNumber(value: value)
      } else if let value = try? singleValueContainer.decode(Double.self) {
        self.value = NSNumber(value: value)
      } else if let value = try? singleValueContainer.decode(String.self) {
        self.value = value
      } else if singleValueContainer.decodeNil() {
        value = NSNull()
      } else {
        throw DecodingError.dataCorruptedError(in: singleValueContainer, debugDescription: "Unexpected value")
      }
    } else {
      let context = DecodingError.Context(codingPath: [], debugDescription: "Invalid data format for JSON")
      throw DecodingError.dataCorrupted(context)
    }
  }

  private struct Key: CodingKey {
    var stringValue: String

    init?(stringValue: String) {
      self.stringValue = stringValue
    }

    var intValue: Int?

    init?(intValue: Int) {
      self.init(stringValue: "\(intValue)")
      self.intValue = intValue
    }
  }
}

请注意，NSNumber 支持数字和布尔类型，否则这样的操作将不起作用：

if customer.metadata["keyForInt"] as? Int64 { // as it always will be nil

Answer 7

最简单和建议的方法是 为 JSON.

中的每个字典或模型创建单独的模型

我就是这样做的

//Model for dictionary **Metadata**

struct Metadata: Codable {
    var link_id: String?
    var buy_count: Int?
}  

//Model for dictionary **Customer**

struct Customer: Codable {
   var object: String?
   var id: String?
   var email: String?
   var metadata: Metadata?
}

//Here is our decodable parser that decodes JSON into expected model

struct CustomerParser {
    var customer: Customer?
}

extension CustomerParser: Decodable {

//keys that matches exactly with JSON
enum CustomerKeys: String, CodingKey {
    case object = "object"
    case id = "id"
    case email = "email"
    case metadata = "metadata"
}

init(from decoder: Decoder) throws {
    let container = try decoder.container(keyedBy: CustomerKeys.self) // defining our (keyed) container

    let object: String = try container.decode(String.self, forKey: .object) // extracting the data
    let id: String = try container.decode(String.self, forKey: .id) // extracting the data
    let email: String = try container.decode(String.self, forKey: .email) // extracting the data

   //Here I have used metadata model instead of dictionary [String: Any]
    let metadata: Metadata = try container.decode(Metadata.self, forKey: .metadata) // extracting the data

    self.init(customer: Customer(object: object, id: id, email: email, metadata: metadata))

    }
}

用法：

  if let url = Bundle.main.url(forResource: "customer-json-file", withExtension: "json") {
        do {
            let jsonData: Data =  try Data(contentsOf: url)
            let parser: CustomerParser = try JSONDecoder().decode(CustomerParser.self, from: jsonData)
            print(parser.customer ?? "null")

        } catch {

        }
    }

**为了安全起见，我在解析时使用了optional，可以根据需要进行更改。

Read more on this topic

Answer 8

我提出了一个稍微不同的解决方案。

假设我们要解析的不仅仅是一个简单的 [String: Any]，Any 可能是一个数组或嵌套字典或数组字典。

像这样：

var json = """
{
  "id": 12345,
  "name": "Giuseppe",
  "last_name": "Lanza",
  "age": 31,
  "happy": true,
  "rate": 1.5,
  "classes": ["maths", "phisics"],
  "dogs": [
    {
      "name": "Gala",
      "age": 1
    }, {
      "name": "Aria",
      "age": 3
    }
  ]
}
"""

嗯，这是我的解决方案：

public struct AnyDecodable: Decodable {
  public var value: Any

  private struct CodingKeys: CodingKey {
    var stringValue: String
    var intValue: Int?
    init?(intValue: Int) {
      self.stringValue = "\(intValue)"
      self.intValue = intValue
    }
    init?(stringValue: String) { self.stringValue = stringValue }
  }

  public init(from decoder: Decoder) throws {
    if let container = try? decoder.container(keyedBy: CodingKeys.self) {
      var result = [String: Any]()
      try container.allKeys.forEach { (key) throws in
        result[key.stringValue] = try container.decode(AnyDecodable.self, forKey: key).value
      }
      value = result
    } else if var container = try? decoder.unkeyedContainer() {
      var result = [Any]()
      while !container.isAtEnd {
        result.append(try container.decode(AnyDecodable.self).value)
      }
      value = result
    } else if let container = try? decoder.singleValueContainer() {
      if let intVal = try? container.decode(Int.self) {
        value = intVal
      } else if let doubleVal = try? container.decode(Double.self) {
        value = doubleVal
      } else if let boolVal = try? container.decode(Bool.self) {
        value = boolVal
      } else if let stringVal = try? container.decode(String.self) {
        value = stringVal
      } else {
        throw DecodingError.dataCorruptedError(in: container, debugDescription: "the container contains nothing serialisable")
      }
    } else {
      throw DecodingError.dataCorrupted(DecodingError.Context(codingPath: decoder.codingPath, debugDescription: "Could not serialise"))
    }
  }
}

尝试使用

let stud = try! JSONDecoder().decode(AnyDecodable.self, from: jsonData).value as! [String: Any]
print(stud)

Answer 9

如果您使用具有 Codable 协议支持的 SwiftyJSON to parse JSON, you can update to 4.1.0。只需声明 metadata: JSON 即可。

import SwiftyJSON

struct Customer {
  let id: String
  let email: String
  let metadata: JSON
}

Answer 10

我做了一个pod，方便解码+编码的方式[String: Any]，[Any]。这提供了编码或解码可选属性，这里 https://github.com/levantAJ/AnyCodable

pod 'DynamicCodable', '1.0'

使用方法：

import DynamicCodable

struct YourObject: Codable {
    var dict: [String: Any]
    var array: [Any]
    var optionalDict: [String: Any]?
    var optionalArray: [Any]?

    enum CodingKeys: String, CodingKey {
        case dict
        case array
        case optionalDict
        case optionalArray
    }

    init(from decoder: Decoder) throws {
        let values = try decoder.container(keyedBy: CodingKeys.self)
        dict = try values.decode([String: Any].self, forKey: .dict)
        array = try values.decode([Any].self, forKey: .array)
        optionalDict = try values.decodeIfPresent([String: Any].self, forKey: .optionalDict)
        optionalArray = try values.decodeIfPresent([Any].self, forKey: .optionalArray)
    }

    func encode(to encoder: Encoder) throws {
        var container = encoder.container(keyedBy: CodingKeys.self)
        try container.encode(dict, forKey: .dict)
        try container.encode(array, forKey: .array)
        try container.encodeIfPresent(optionalDict, forKey: .optionalDict)
        try container.encodeIfPresent(optionalArray, forKey: .optionalArray)
    }
}

Answer 11

extension ViewController {

    func swiftyJson(){
        let url = URL(string: "https://itunes.apple.com/search?term=jack+johnson")
        //let url = URL(string: "http://makani.bitstaging.in/api/business/businesses_list")

        Alamofire.request(url!, method: .get, parameters: nil).responseJSON { response in
            var arrayIndexes = [IndexPath]()
            switch(response.result) {
            case .success(_):

                let data = response.result.value as! [String : Any]

                if let responseData =  Mapper<DataModel>().map(JSON: data) {
                    if responseData.results!.count > 0{
                        self.arrayExploreStylistList = []
                    }
                    for i in 0..<responseData.results!.count{
                        arrayIndexes.append(IndexPath(row: self.arrayExploreStylistList.count + i, section: 0))
                    }
                    self.arrayExploreStylistList.append(contentsOf: responseData.results!)

                    print(arrayIndexes.count)

                }

                //                    if let arrNew = data["results"] as? [[String : Any]]{
                //                        let jobData = Mapper<DataModel>().mapArray(JSONArray: arrNew)
                //                        print(jobData)
                //                        self.datamodel = jobData
                //                    }
                self.tblView.reloadData()
                break

            case .failure(_):
                print(response.result.error as Any)
                break

            }
        }

    }
}

Answer 12

使用解码器和编码密钥进行解码

public let dataToDecode: [String: AnyDecodable]

enum CodingKeys: CodingKey {
    case dataToDecode
}

init(from decoder: Decoder) throws {
    let container = try decoder.container(keyedBy: CodingKeys.self)
    self.dataToDecode = try container.decode(Dictionary<String, AnyDecodable>.self, forKey: .dataToDecode) 
}

Answer 13

详情

Xcode 12.0.1 (12A7300)
Swift 5.3

基于库

// code from: https://github.com/levantAJ/AnyCodable/blob/master/AnyCodable/DecodingContainer%2BAnyCollection.swift

private
struct AnyCodingKey: CodingKey {
    let stringValue: String
    private (set) var intValue: Int?
    init?(stringValue: String) { self.stringValue = stringValue }
    init?(intValue: Int) {
        self.intValue = intValue
        stringValue = String(intValue)
    }
}

extension KeyedDecodingContainer {

    private
    func decode(_ type: [Any].Type, forKey key: KeyedDecodingContainer<K>.Key) throws -> [Any] {
        var values = try nestedUnkeyedContainer(forKey: key)
        return try values.decode(type)
    }

    private
    func decode(_ type: [String: Any].Type, forKey key: KeyedDecodingContainer<K>.Key) throws -> [String: Any] {
        try nestedContainer(keyedBy: AnyCodingKey.self, forKey: key).decode(type)
    }

    func decode(_ type: [String: Any].Type) throws -> [String: Any] {
        var dictionary: [String: Any] = [:]
        for key in allKeys {
            if try decodeNil(forKey: key) {
                dictionary[key.stringValue] = NSNull()
            } else if let bool = try? decode(Bool.self, forKey: key) {
                dictionary[key.stringValue] = bool
            } else if let string = try? decode(String.self, forKey: key) {
                dictionary[key.stringValue] = string
            } else if let int = try? decode(Int.self, forKey: key) {
                dictionary[key.stringValue] = int
            } else if let double = try? decode(Double.self, forKey: key) {
                dictionary[key.stringValue] = double
            } else if let dict = try? decode([String: Any].self, forKey: key) {
                dictionary[key.stringValue] = dict
            } else if let array = try? decode([Any].self, forKey: key) {
                dictionary[key.stringValue] = array
            }
        }
        return dictionary
    }
}

extension UnkeyedDecodingContainer {
    mutating func decode(_ type: [Any].Type) throws -> [Any] {
        var elements: [Any] = []
        while !isAtEnd {
            if try decodeNil() {
                elements.append(NSNull())
            } else if let int = try? decode(Int.self) {
                elements.append(int)
            } else if let bool = try? decode(Bool.self) {
                elements.append(bool)
            } else if let double = try? decode(Double.self) {
                elements.append(double)
            } else if let string = try? decode(String.self) {
                elements.append(string)
            } else if let values = try? nestedContainer(keyedBy: AnyCodingKey.self),
                let element = try? values.decode([String: Any].self) {
                elements.append(element)
            } else if var values = try? nestedUnkeyedContainer(),
                let element = try? values.decode([Any].self) {
                elements.append(element)
            }
        }
        return elements
    }
}

解决方案

struct DecodableDictionary: Decodable {
    typealias Value = [String: Any]
    let dictionary: Value?
    init(from decoder: Decoder) throws {
        dictionary = try? decoder.container(keyedBy: AnyCodingKey.self).decode(Value.self)
    }
}

用法

struct Model: Decodable {
    let num: Double?
    let flag: Bool?
    let dict: DecodableDictionary?
    let dict2: DecodableDictionary?
    let dict3: DecodableDictionary?
}

let data = try! JSONSerialization.data(withJSONObject: dictionary)
let object = try JSONDecoder().decode(Model.self, from: data)
print(object.dict?.dictionary)      // prints [String: Any]
print(object.dict2?.dictionary)     // prints nil
print(object.dict3?.dictionary)     // prints nil

Answer 14

我写了一篇文章 repo 帮助添加 [String: Any] 对 Codable 的解码和编码支持。

https://medium.com/nerd-for-tech/string-any-support-for-codable-4ba062ce62f2

这在可解码方面有所改进，并且还添加了可编码支持作为

中给出的解决方案

你将能够实现的目标：

json:

示例代码：

Answer 15

这会起作用

public struct AnyDecodable: Decodable {
    public let value: Any

    public init<T>(_ value: T?) {
        self.value = value ?? ()
    }
}

let contentDecodable = try values.decodeIfPresent(AnyDecodable.self, forKey: .content)

Answer 16

我使用了关于这个主题的一些答案来获得对我来说最简单的解决方案。我的问题是我收到了 [String: Any] 类型的字典，但我可以很好地处理 [String: String] 转换字符串中的每个其他 Any 值。所以这是我的解决方案：

struct MetadataType: Codable {
    let value: String?

    private init(_ value: String?) {
        self.value = value
    }

    init(from decoder: Decoder) throws {
        let container = try decoder.singleValueContainer()

        if let decodedValue = try? container.decode(Int.self) {
            self.init(String(decodedValue))
        } else if let decodedValue = try? container.decode(Double.self) {
            self.init(String(decodedValue))
        } else if let decodedValue = try? container.decode(Bool.self) {
            self.init(String(decodedValue))
        } else if let decodedValue = try? container.decode(String.self) {
            self.init(decodedValue)
        } else {
            self.init(nil)
        }
    }
}

并且在声明我的字典时，我使用

let userInfo: [String: MetadataType]

如何在 Swift [45] 可解码协议中解码具有 JSON 字典类型的属性

How to decode a property with type of JSON dictionary in Swift [45] decodable protocol

json

swift

swift4

codable

扩展

详情

基于库

解决方案

用法

如何在 Swift [45] 可解码协议中解码具有 JSON 字典类型的 属性

How to decode a property with type of JSON dictionary in Swift [45] decodable protocol

json

swift

swift4

codable

扩展

详情

基于库

解决方案

用法

如何在 Swift [45] 可解码协议中解码具有 JSON 字典类型的属性