ios - 解码具有不同类型的 Json 对象

Question

我有一个用于填充 TableView 的 Json 数据。Json 的主要部分有两种类型的对象，分别是“Main”和 n-number tableview 对象；

主对象中有两个字符串类型(“url”和“bar_name”)。 Tableview 对象有 3 种类型(“name”、“id”、[tableData])。这对于所有 tableview 对象(n 个)都是常见的。填充单元格的 Tabledata 对象有 3 种不同的类型，因为一种打开一个 url，另一种打开一个新表，最后一个只做一个 Action 。

我想将这种类型的 json 解码为结构。可能吗？

    //For All Types
protocol commonCellTypes: Codable{
    var type: Int { get }

}
struct User: Codable{
    let mainPage: MainPage?
    let tables: [table]?
}
struct MainPage: Codable{
    let url: String?
    let bar_name: String?
}
struct table: Codable{
    let name: String?
    let id: String?
    let Cells: [commonCellTypes]

    enum CodeKeys: CodingKey
    {
        case name
        case id
        case tableDatas
    }

    init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodeKeys.self)
        name = try container.decode (String.self, forKey: .name)
        id = try container.decode (String.self, forKey: .id)
        Cells = try container.decode ([commonCellTypes].self, forKey: .tableDatas)
    }

    func encode(to encoder: Encoder) throws
    {
        var container = encoder.container(keyedBy: CodeKeys.self)
        try container.encode (name, forKey: .name)
        try container.encode (id, forKey: .id)
        try container.encode (Cells, forKey: .tableDatas)
    }
}
//Type 2
struct cellType2: commonCellTypes{
    let cellText: String
    let imageName: String?
    let url: URL?
    let type: Int
}
//Type 1
struct cellType1: commonCellTypes{
    let cellText: String
    let imageName: String
    let table_id: String
    let type: Int
}
//Type 0
struct cellType0: commonCellTypes{
    let cellText: String
    let imageName: String
    let type: Int
    let action: String
}

编辑:我找到了一个类似的帖子，但不适用于我的情况。我遇到错误

Type ' table' does not conform to protocol 'Encodable'

Swift JSONDecoder with multiple structures

EDIT2:我添加了解码代码，但 mainPage 和 User 都为零。我的结构缺少什么？

  let data = try Data(contentsOf: URL(fileURLWithPath: path), options: .alwaysMapped)
            let decoder = JSONDecoder()
            let admin = try! decoder.decode(User.self, from: data)
            print(admin)

Answer 1

您应该为解码实现自定义初始化器，为编码实现encode(to encoder: Encoder)。试试这个:

//For All Types
protocol commonCellTypes: Codable{

}
struct MainStruct: Codable{
    let tables: [table]
}
struct table: Codable{
    let name: String?
    let id: String?
    let tableDatas: [commonCellTypes]

    enum CodeKeys: CodingKey
    {
    case name
    case id
    case tableDatas
    }

    init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodeKeys.self)
        name = try container.decode (String.self, forKey: .name)
        id = try container.decode (String.self, forKey: .id)
        tableDatas = try container.decode ([commonCellTypes].self, forKey: .tableDatas)
    }

    func encode(to encoder: Encoder) throws
    {
        var container = encoder.container(keyedBy: CodeKeys.self)
        try container.encode (name, forKey: .name)
        try container.encode (id, forKey: .id)
        try container.encode (tableDatas, forKey: .tableDatas)
    }
}
//Type 2
struct cellType2: commonCellTypes{
    let cellText: String
    let imageName: String?
    let url: URL?
    let type: Int
}
//Type 1
struct cellType1: commonCellTypes{
    let cellText: String
    let imageName: String
    let table_id: String
    let type: Int
}
//Type 0
struct cellType0: commonCellTypes{
    let cellText: String
    let imageName: String
    let type: Int
    let action: String
}