ios - 在 NSDictionary 的数组对象中访问第二层数组

Question

我正在尝试 NSDictionary 的数组对象中的第二级数组，但它返回 nil

我首先定义了 NSDictionary 然后访问了数组的第一层，直到现在一切都很好。

let dict = JSON(responseObject as! NSDictionary)
let arrayData = dict["data"].arrayObject! as NSArray
print("arrayData", arrayData)

当打印 arrayData 时，我得到以下返回值

data =     (
{
categories = (
    {
    categories = "<null>";
    "category_id" = 333;
    image = "https://www.example.com/images/1.jpg";
    name = "Sub Category One";
    "parent_id" = 1000;
    },
    {
    categories = "<null>";
    "category_id" = 444;
    image = "https://www.example.com/images/2.jpg";
    name = "Sub Category Two";
    "parent_id" = 1000;
    },
    {
    categories = "<null>";
    "category_id" = 555;
    image = "https://www.example.com/images/3.jpg";
    name = "Sub Category Three";
    "parent_id" = 1000;
    }
);//end of categories array
"category_id" = 1000;
image = "https://www.examples.com/images/category.jpg";
name = "Parent Category";
"parent_id" = 0;
},
)

现在我正在尝试从上面返回的数组中访问和打印类别

所以我尝试了以下方法:

if dict["categories"].arrayObject != nil{
  let arrayData2 = dict["categories"].arrayObject! as NSArray
  print("arrayData2", arrayData2)
}

我也试过

if dict["data"]["categories"].arrayObject != nil{
  let arrayData2 = dict["data"]["categories"].arrayObject! as NSArray
  print("arrayData2", arrayData2)
}

两种方式我都得到了 nil 值，而它应该得到真正的值。

已编辑:在 ViewController 和 dataModel 结构中添加了 API 调用

View Controller中调用HTTPAPI函数

func callingHttppApi(){
  DispatchQueue.main.async{
    NetworkManager.sharedInstance.showLoader()
    let sessionId = self.defaults.object(forKey:"token");
    self.categoriesTableView.isUserInteractionEnabled = false

      var requstParams = [String:Any]();
      requstParams["token"] = sessionId
      NetworkManager.sharedInstance.callingHttpRequest(params:requstParams, apiname:"api/cat", cuurentView: self){success,responseObject in
        if success == 1{
          let dict = responseObject as! NSDictionary;
          if dict.object(forKey: "fault") != nil{
            let fault = dict.object(forKey: "fault") as! Bool;
            if fault == true{
              self.loginRequest()
            }
          }else{
            NetworkManager.sharedInstance.dismissLoader()
            self.view.isUserInteractionEnabled = true
            self.categoriesTableView.isUserInteractionEnabled = true
            let dict = JSON(responseObject as! NSDictionary)
            let arrayData = dict["data"].arrayObject! as NSArray
            if dict["categories"].arrayObject != nil{
              let arrayData2 = dict["categories"].arrayObject! as NSArray
              print("arrayData2", arrayData2)
            }
            print("arrayData", arrayData)
            if dict["error"].intValue == 1{
              NetworkManager.sharedInstance.showErrorMessageWithBack(view: self, message: NetworkManager.sharedInstance.language(key: "error"))
            }else{
              self.categoriesCollModel = CategoriesViewModel(data:JSON(responseObject as! NSDictionary))
              dump (self.categoriesCollModel)
            }
          }
        }else if success == 2{
          NetworkManager.sharedInstance.dismissLoader()
          self.callingHttppApi()
        }
      }
    }
  }

用于转换值的数据模型结构

//
//  CategoriesViewModel.swift
//

import Foundation

class Categories: NSObject{
    var id:String = ""
    var name:String = ""
    var image:String = ""

    init(data:JSON){
        self.id = data["category_id"].stringValue
        self.name  = data["name"].stringValue
        self.image = data["image"].stringValue
    }

}

class SubCategories:NSObject{
    var pid:String = ""
    var id:String = ""
    var name:String = ""
    var image:String = ""

    init(data:JSON) {
        self.pid = data["parent_id"].stringValue
        self.id = data["category_id"].stringValue
        self.name  = data["name"].stringValue
        self.image = data["image"].stringValue
    }

}

struct Categories_Data{
    var id:String = ""
    var categoriesArray = [SubCategories]()

    init(data:JSON) {
        self.id = data["category_id"].stringValue
        if let arrayData = data["data"]["categories"].arrayObject {
            categoriesArray =  arrayData.map({(value) -> SubCategories in
                return  SubCategories(data:JSON(value))
            })
        }
    }

}

class CategoriesViewModel:NSObject{
    var categoryModel = [Categories]()
    var subCategories = [SubCategories]()
  var categories_Data = [Categories_Data]()

    init(data:JSON) {

        let arrayData = data["data"].arrayObject! as NSArray
        categoryModel =  arrayData.map({(value) -> Categories in
            return  Categories(data:JSON(value))
        })

        if data["data"]["categories"].arrayObject != nil{
            let arrayData2 = data["data"]["categories"].arrayObject! as NSArray
            categories_Data =  arrayData2.map({(value) -> Categories_Data in
                return  Categories_Data(data:JSON(value))
            })
        }

        //categoryModel = Categories(data:data)


    }

    var getCategories:Array<Categories>{
        return categoryModel
    }

  var getSubCategories:Array<SubCategories>{
        return subCategories
    }

}

Answer 1

我强烈建议放弃 SwiftyJSON 并使用 Decodable。

CategoriesViewModel 可以简化为

struct Root: Decodable {
    let data : [Category]
}

struct Category: Decodable {
    let categories : [Category]?
    let categoryId : Int
    let image : URL
    let name : String
    let parentId : Int
}

您需要从网络请求中获取原始数据(在以下名为 data 的代码中)，然后您可以简单地将数据解码为结构并使用点符号获取值。

我添加了一个辅助函数来递归打印嵌套类别

do {
    let decoder = JSONDecoder()
    decoder.keyDecodingStrategy = .convertFromSnakeCase
    let result = try decoder.decode(Root.self, from: data)
    printCategories(result.data)
} catch { print(error) }

func printCategories(_ categories : [Category]) {
    for item in categories {
        if let subCategories = item.categories {
            printCategories(subCategories)
        }
        print(item.name, item.categoryId)
    }
}