从JSON解码为PropertyWrapper。

Question

我想将JSON字符串解码为 People 如下所示。该 age 是数字(Int)类型，而下面的代码得到错误。

"Expected to decode Dictionary<String, Any> but found a number instead."

我认为这意味着 @Age 被视为 Dictionary<String, Any>.

任何方法来解码JSON值 PropertyWrapper 属性？

let jsonString =
"""
{
"name": "Tim",
"age": 28
}
"""

@propertyWrapper
struct Age: Codable {
    var age: Int = 0
    var wrappedValue: Int {
        get {
            return age
        }

        set {
            age = newValue * 10
        }
    }
}

struct People: Codable {
    var name: String
    @Age var age: Int
}

let jsonData = jsonString.data(using: .utf8)!
let user = try! JSONDecoder().decode(People.self, from: jsonData)
print(user.name)
print(user.age)

Answer 1

谢谢你的评论，添加这个让它工作。

extension People {
    init(from decoder: Decoder) throws {
        let values = try decoder.container(keyedBy: CodingKeys.self)

        name = try values.decode(String.self, forKey: .name)
        age = try values.decode(Int.self, forKey: .age)
    }
}