ios - Swift - 如何将平面 json 解码为嵌套结构?
问题描述
假设我有以下 JSON,我想将其解码为特定结构。我该怎么做呢
JSON:
{
"fullName": "Federico Zanetello",
"id": 123456,
"twitter": "http://twitter.com/zntfdr",
"results": ["mate","bate"]
}
解码结构
struct Response {
let data: UserData,
let results: [String]
}
UserData
结构_
Struct UserData {
let fullName: String,
let id: Int,
let twitter: String
}
我做了我的研究,找不到有效的解决方案。这是我到目前为止写的代码
struct UserData: Decodable {
let fullName: String
let id: Int
let twitter: String
enum CodingKeys: String, CodingKey {
case fullName
case id
case twitter
}
init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
self.fullName = try container.decode(String.self, forKey: .fullName)
self.id = try container.decode(Int.self, forKey: .id)
self.twitter = try container.decode(String.self, forKey: .twitter)
}
}
struct Respone: Decodable{
let data: UserData
let results: [String]
}
let json = """
{
"fullName": "Federico Zanetello",
"id": 123456,
"twitter": "http://twitter.com/zntfdr",
"results": ["mate","bate"]
}
""".data(using: .utf8)! // our data in native (JSON) format
let myStruct = try JSONDecoder().decode(MetaData.self, from: json) // Decoding our data
print(myStruct)
我收到 KeynotFound 错误,因为data
JSON 中不存在密钥。我该如何解决这个问题?
解决方案
你可以这样做:
struct UserData: Decodable {
let fullName: String
let id: Int
let twitter: String
}
struct Response: Decodable{
let data: UserData
let results: [String]
enum CodingKeys : CodingKey {
case results
}
init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
results = try container.decode([String].self, forKey: .results)
data = try decoder.singleValueContainer().decode(UserData.self)
}
}
诀窍是在 中使用自定义解码Response
,然后像平常一样解码后results
,得到一个singleValueContainer
. 此容器将包含 JSON 中的所有密钥,因此您可以使用此容器来解码UserData
.