如何将字典转换为数组以填充表格视图

Question

我正在尝试将从此返回的字典转换为来自 Message 结构的数组以填充表格视图。在这样做的过程中，我遇到了一个错误，显示为

"keyNotFound(CodingKeys(stringValue: "messages", intValue: nil), Swift.DecodingError.Context(codingPath: [], debugDescription: "No value associated with"

我该如何解决这个问题？请看下面的代码：

  struct MessageResponse: Codable {
        let messages: [Message]
    }
    
    struct Message:Codable {
        
        var userID: String
        var username: String
        var avatarURL: String
        var text: String
        var messages:[String] = []
       
        enum CodingKeys: String, CodingKey {
            case userID = "user_id"
            case username = "name"
            case avatarURL = "avatar_url"
            case messages = "message"
        }
        
        init(from decoder: Decoder) throws {
            let values = try decoder.container(keyedBy: CodingKeys.self)
            userID = try values.decodeIfPresent(String.self, forKey: .userID) ?? ""
            username = try values.decodeIfPresent(String.self, forKey: .username) ?? ""
            avatarURL = try values.decodeIfPresent(String.self, forKey: .avatarURL) ?? ""
            text = try values.decodeIfPresent(String.self, forKey: .messages) ?? ""
           
            for message in messages{
                let chatInfo =  try values.decodeIfPresent(String.self, forKey: Message.CodingKeys(rawValue:message)!)
                messages.append(chatInfo ?? "")
            }
   

func getChat(){
        ChatClient.shared.getMessages {  messageResponse in
            print(self.messages = messageResponse.messages)
        }
        
    }        }
           

---

这是我要解码的 JSON

{ "data" : [ { "user_id" : "1", "name" : "Drew", "avatar_url" : "http://dev.rapptrlabs.com/Tests/images/drew_avatar.png", "message" : "Team, can we give job applicants taking this test some examples of the types of apps they’d be working on if they joined our team?" }, { "user_id" : "2", "name" : "Abby", "avatar_url" : "http://dev.rapptrlabs.com/Tests/images/abby_avatar.png", "message" : "We work on ecommerce apps for brands like PromGirl & Simply Dresses." }, { "user_id" : "3", "name" : "Taylor", "avatar_url" : "http://dev.rapptrlabs.com/Tests/images/taylor_avatar.png", "message" : "You know those scooter sharing services that have been popping up? We developed and support one of those: Movo." }, { "user_id" : "2", "name" : "Abby", "avatar_url" : "http://dev.rapptrlabs.com/Tests/images/abby_avatar.png", "message" : "We do a lot of hardware-pairing apps as well like Conair’s Smart WeightWatchers Scale and Phlex’s new smart goggles." } ] }

Answer 1

无需创建自定义解码器。除此之外，您的主要问题是您的 MessageResponse messages 属性键应该是“数据”

---

// MARK: - MessageResponse
struct MessageResponse: Codable {
    let messages: [Message]
    enum CodingKeys: String, CodingKey {
        case messages = "data"
    }
}

---

// MARK: - Message
struct Message: Codable {
    let userID, name: String
    let avatarURL: String
    let message: String
    enum CodingKeys: String, CodingKey {
        case userID = "user_id", name, avatarURL = "avatar_url", message
    }
}

---

游乐场测试：

let json = """
{ "data" : [ { "user_id" : "1", "name" : "Drew", "avatar_url" : "http://dev.rapptrlabs.com/Tests/images/drew_avatar.png", "message" : "Team, can we give job applicants taking this test some examples of the types of apps they’d be working on if they joined our team?" }, { "user_id" : "2", "name" : "Abby", "avatar_url" : "http://dev.rapptrlabs.com/Tests/images/abby_avatar.png", "message" : "We work on ecommerce apps for brands like PromGirl & Simply Dresses." }, { "user_id" : "3", "name" : "Taylor", "avatar_url" : "http://dev.rapptrlabs.com/Tests/images/taylor_avatar.png", "message" : "You know those scooter sharing services that have been popping up? We developed and support one of those: Movo." }, { "user_id" : "2", "name" : "Abby", "avatar_url" : "http://dev.rapptrlabs.com/Tests/images/abby_avatar.png", "message" : "We do a lot of hardware-pairing apps as well like Conair’s Smart WeightWatchers Scale and Phlex’s new smart goggles." } ] }
"""

---

do {
    let response = try JSONDecoder().decode(MessageResponse.self, from: Data(json.utf8))
    print(response)
} catch {
    print(error)
}

---

这将打印：

MessageResponse(messages: [__lldb_expr_9.Message(userID: "1", name: "Drew", avatarURL: "http://dev.rapptrlabs.com/Tests/images/drew_avatar.png", message: "Team , 我们能否给参加此测试的求职者一些示例，说明他们加入我们团队后将使用的应用程序类型？"), __lldb_expr_9.Message(userID: "2", name: "Abby", avatarURL: " http://dev.rapptrlabs.com/Tests/images/abby_avatar.png", message: "我们为 PromGirl & Simply Dresses 等品牌开发电子商务应用程序。"), __lldb_expr_9.Message(userID: "3", name: "Taylor", avatarURL: "http://dev.rapptrlabs.com/Tests/images/taylor_avatar.png", message: "你知道那些已经出现的滑板车共享服务吗？我们开发并支持其中之一：Movo ."), __lldb_expr_9.Message(userID: "2", name: "Abby", avatarURL: "http://dev.rapptrlabs.com/Tests/images/abby_avatar.png", message: "我们做了很多硬件配对应用程序以及 Conair 的 Smart WeightWatchers Scale 和 Phlex 的新型智能护目镜。")])