Ios Swift 4 JSON解码根数组

我在使用Swift 4解码功能解码JSON响应时遇到问题。 我有一个主结构，它有一个内部结构var hr_employees:[employeen]？=[]. 问题在于“var hr_employees:[employeen]”的JSON映射不正确[…]

我得到了响应状态、访问级别和会话令牌三个根值的正确值

////////////结构的代码////////////////////////

struct EmployeeData: Codable {
     var response_status:Int=0
     var access_level:Int=0
     var session_token:String=""
     var hr_employees: [Employee]? = []
}

private enum CodingKeys: String, CodingKey {
        case response_status="response_status"
        case access_level="access_level"
        case session_token="session_token"
        case hr_employees="hr_employees"
    }

    init() {

    }



init(from decoder: Decoder) throws {
            let values = try decoder.container(keyedBy: CodingKeys.self)
            response_status = try values.decode(Int.self, forKey: .response_status)
            do{
                session_token = try values.decode(String.self, forKey: .session_token)
            }catch {
                print( "No value associated with key title (\"session_token\").")
            }
            do{
                access_level = try values.decode(Int.self, forKey: .access_level)
            }
            catch {
                print( "No value associated with key access_level ")
            }
        }

  struct Employee: Codable {
        var userId:Int=0
        var nameFirst:String=""
        var nameLast:String=""
        var position:String=""
        var company:String=""
        var supervisor:String=""
        var assistant:String=""
        var phone:String=""
        var email:String=""
        var address:String=""
        var gender:String=""
        var age:Int=0
        var nationality:String=""
        var firstLanguage:String=""
        var inFieldOfView:String = "0"
        var photo:String="user-default"
        var status:String="3"
    }

{
"response_status":1
,"access_level":2
,"hr_employees":[
{
"user_id":4226
,"name_last":"Sampe"
,"name_first":"Frederica"
,"position":"Systems Maint"
,"phone":"123456"
,"email":"omega@demo.mobile"
,"address":"00100 Helsinki 1"
,"age":67
,"company":"Omega Enterprise"
}
,{
"user_id":5656
,"name_last":"Aalto"
,"name_first":"Antero"
,"position":"Programming Methodology and Languages Researcher"
,"supervisor":"Mayo Georgia"
,"phone":"123456"
,"email":"omega@demo.mobile"
,"address":"00100 Finland "
,"age":51
,"company":"Omega Fire Related Equipment"
}
]
}

/////////////////内部结构///////////////////////

struct EmployeeData: Codable {
     var response_status:Int=0
     var access_level:Int=0
     var session_token:String=""
     var hr_employees: [Employee]? = []
}

private enum CodingKeys: String, CodingKey {
        case response_status="response_status"
        case access_level="access_level"
        case session_token="session_token"
        case hr_employees="hr_employees"
    }

    init() {

    }



init(from decoder: Decoder) throws {
            let values = try decoder.container(keyedBy: CodingKeys.self)
            response_status = try values.decode(Int.self, forKey: .response_status)
            do{
                session_token = try values.decode(String.self, forKey: .session_token)
            }catch {
                print( "No value associated with key title (\"session_token\").")
            }
            do{
                access_level = try values.decode(Int.self, forKey: .access_level)
            }
            catch {
                print( "No value associated with key access_level ")
            }
        }

  struct Employee: Codable {
        var userId:Int=0
        var nameFirst:String=""
        var nameLast:String=""
        var position:String=""
        var company:String=""
        var supervisor:String=""
        var assistant:String=""
        var phone:String=""
        var email:String=""
        var address:String=""
        var gender:String=""
        var age:Int=0
        var nationality:String=""
        var firstLanguage:String=""
        var inFieldOfView:String = "0"
        var photo:String="user-default"
        var status:String="3"
    }

{
"response_status":1
,"access_level":2
,"hr_employees":[
{
"user_id":4226
,"name_last":"Sampe"
,"name_first":"Frederica"
,"position":"Systems Maint"
,"phone":"123456"
,"email":"omega@demo.mobile"
,"address":"00100 Helsinki 1"
,"age":67
,"company":"Omega Enterprise"
}
,{
"user_id":5656
,"name_last":"Aalto"
,"name_first":"Antero"
,"position":"Programming Methodology and Languages Researcher"
,"supervisor":"Mayo Georgia"
,"phone":"123456"
,"email":"omega@demo.mobile"
,"address":"00100 Finland "
,"age":51
,"company":"Omega Fire Related Equipment"
}
]
}

////////////以下是JSON//////////////////////

struct EmployeeData: Codable {
     var response_status:Int=0
     var access_level:Int=0
     var session_token:String=""
     var hr_employees: [Employee]? = []
}

private enum CodingKeys: String, CodingKey {
        case response_status="response_status"
        case access_level="access_level"
        case session_token="session_token"
        case hr_employees="hr_employees"
    }

    init() {

    }



init(from decoder: Decoder) throws {
            let values = try decoder.container(keyedBy: CodingKeys.self)
            response_status = try values.decode(Int.self, forKey: .response_status)
            do{
                session_token = try values.decode(String.self, forKey: .session_token)
            }catch {
                print( "No value associated with key title (\"session_token\").")
            }
            do{
                access_level = try values.decode(Int.self, forKey: .access_level)
            }
            catch {
                print( "No value associated with key access_level ")
            }
        }

  struct Employee: Codable {
        var userId:Int=0
        var nameFirst:String=""
        var nameLast:String=""
        var position:String=""
        var company:String=""
        var supervisor:String=""
        var assistant:String=""
        var phone:String=""
        var email:String=""
        var address:String=""
        var gender:String=""
        var age:Int=0
        var nationality:String=""
        var firstLanguage:String=""
        var inFieldOfView:String = "0"
        var photo:String="user-default"
        var status:String="3"
    }

{
"response_status":1
,"access_level":2
,"hr_employees":[
{
"user_id":4226
,"name_last":"Sampe"
,"name_first":"Frederica"
,"position":"Systems Maint"
,"phone":"123456"
,"email":"omega@demo.mobile"
,"address":"00100 Helsinki 1"
,"age":67
,"company":"Omega Enterprise"
}
,{
"user_id":5656
,"name_last":"Aalto"
,"name_first":"Antero"
,"position":"Programming Methodology and Languages Researcher"
,"supervisor":"Mayo Georgia"
,"phone":"123456"
,"email":"omega@demo.mobile"
,"address":"00100 Finland "
,"age":51
,"company":"Omega Fire Related Equipment"
}
]
}

---

一个问题是JSON中的内容与您对Employee的定义不匹配。例如，

nameFirst

不存在，而

name\u first

不存在

---

另一个原因是，您有一个

init（from:）

的自定义实现，它从不获取

hr\u employees

值

有很多地方需要改进：

您的

Struct

s可以得到改进，以利用

Codable

协议的自动化功能

您需要了解为什么要使用

CodingKeys

enum

• 对你来说。。。还有最好放在哪里（提示：在

  Struct

  本身内部）

您需要知道哪些参数需要是可选的以及为什么

• 当然，这取决于您的json结构

如果参数有一个默认值，那么需要遵循一个完全不同的过程；就像拥有自己的

init（from:Decoder）

• 在某种程度上，你必须这样做，但在当前状态下，你并不能真正处理所有的事情

---

根据给定的JSON示例，您可以简单地执行以下操作。
但是…请注意，这不是为了提供默认值而设计的。i、 e.如果json中缺少键，例如

status

，则

Employee

结构中的参数

status

将为

nil

，而不是默认值

“3”

---

---

检查：

do {
    let employeeData = try JSONDecoder().decode(EmployeeData.self,
                                                from: jsonAsData)
    print(employeeData)
}
catch {
    /*
     If it comes here then debug, it's most probably nil keys
     meaning you need more optional parameters in your struct
     */
    print(error)
}

---

如果您希望在

结构中使用默认值，并且上面的示例是一个dealbreaker，请检查以下答案：