Codable class 不符合“可解码”协议

Question

尝试在结构中添加枚举 Codingkeys，但它显示错误 Codable doesn't conform Decodable。

为什么我会收到一致的可解码错误？ 我应该分开结构吗？

struct Model: Codable {
    let aps: Aps
    let link: String?
    let checkAction: String?
   
    enum CodingKeys: String, CodingKey {
           case aps ,link, alert,sound,title,body
           case checkAction = "gcm.notificaiton.check_action"
    }
    
    struct Aps: Codable {
        let alert: Alert
        let sound: String?
       
        
        struct Alert: Codable {
            let title: String?
            let body: String?
        }
    }
   

}

是否必须像下面这样分离结构？

struct FCMModel: Codable {
    let aps: Aps
    let link: String?
    let checkAction: String?
   
    enum CodingKeys: String, CodingKey {
           case aps ,link
           case checkAction = "gcm.notificaiton.check_action"
    }
    

}
struct Aps: Codable {
    let alert: Alert
    let sound: String?
   
    
    struct Alert: Codable {
        let title: String?
        let body: String?
    }
}

Answer 1

没有必要分离结构。 发生错误是因为您在CodingKeys枚举中添加了太多键。 如果您只保留所需的，那么它将起作用：

struct Model: Codable {
    let aps: Aps
    let link: String?
    let checkAction: String?
   
    enum CodingKeys: String, CodingKey {
           case aps ,link
           case checkAction = "gcm.notificaiton.check_action"
    }
    
    struct Aps: Codable {
        let alert: Alert
        let sound: String?
       
        
        struct Alert: Codable {
            let title: String?
            let body: String?
        }
    }
}

alert 、 sound等不是Model的编码键。 它们是Aps的编码键。 不必在Aps中指定它们，因为它们与属性名称相同。