使用编码键排除被解码的值

Question

我有以下结构来解码JSON数据：

更新：

struct Section {
    let owner : String
    var items : [ValueVariables]
}

struct ValueVariables : Decodable {
    var isSelected = false
    let breed: String
    let color: String
    let tagNum: Int

    // other members 
}

问题是isSelected不是被解码的值，我怎样才能排除它被解码以防止它导致这样的错误：

keyNotFound(CodingKeys(stringValue: "isSelected", intValue: nil), Swift.DecodingError.Context(codingPath: [_JSONKey(stringValue: "Index 0", intValue: 0)], debugDescription: "No value associated with key CodingKeys(stringValue: \"isSelected\", intValue: nil) (\"isSelected\"), converted to is_selected.", underlyingError: nil))

我试过像这样使用编码键，但它似乎不起作用:

private enum CodingKeys : String, CodingKey {
    case isSelected = "isSelected"
}

应用答案：

struct ValueVariables : Decodable {

    private enum CodingKeys : String, CodingKey {
        case breed, color, tagNum
    }

    var isSelected = false
    let breed: String
    let color: String
    let tagNum: Int
}

JSON看起来像这样：

[{"breed":"dog","color":"black","tagNum":20394}]

收到错误：

Type 'ValueVariables' does not conform to protocol 'Decodable'

Answer 1

反之，您必须指定要解码的所有密钥。

struct ValueVariables : Decodable {

    private enum CodingKeys : String, CodingKey {
        case breed, color
    }

    var isSelected = false
    let breed: String
    let color: String
}

使用编码键排除被解码的值

Using Coding Keys to exclude values from being decoded

swift

decodable