for loop cycle 始终显示 HTTP 请求后的最后一个数组值 swift 3

Question

我已经使用另一个 post 解决了部分问题，所以现在我可以等待请求结束。我用 Almofire 发出了一个 http 请求并解析了生成的 JSON 文件。我认为 myGroup.notify 中的代码在请求完成后正确执行（如果我打印 allCards.count returns 正确的值）。为什么如果我把 for 循环放在里面它总是显示最后一张牌？

感谢您的帮助

import UIKit
mport SwiftyJSON
import Alamofire

class ViewController: UIViewController {
//variables Declaration
var allCard = [Card]()
let allCardsHTTP: String = "https://omgvamp-hearthstone-v1.p.mashape.com/cards?mashape-key="

override func viewDidLoad() {
    super.viewDidLoad()
    let myGroup = DispatchGroup()

    //get HTTp request with Alamofire

    myGroup.enter()
    Alamofire.request(allCardsHTTP, method: .get).responseJSON {
         response in
         if response.result.isSuccess {
             let jsonCards : JSON = JSON(response.result.value!)
             print("success")
             self.updateJSONCards(json: jsonCards)
          }
        else {
             print("error")
         }
         myGroup.leave()
    }

    myGroup.notify(queue: .main) {
         //Updte UI here
         print(self.allCard[10].name) //This is Working

         for card in self.allCard {
            if card.cardsSet == "Basic" {
                print(card.name)
            }
        } //For loop always showing last card ???


    }
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


//MARK: - JSON Parsing


//Write the updateJSONCards method here:
func updateJSONCards(json: JSON) {
    //create the cards
     for (set, value) in json {
         var card = Card()
         card.cardsSet = set
         if json[set].count != 0 {
            for i in 0...json[set].count - 1 {
                card.name = json[set][i]["name"].stringValue
                allCard.append(card)
             }
         }
         else {
             print("The set \(set) has no cards")
         }
     }
  }

}

Answer 1

您在错误的地方创建了 Card 实例。

在内部重复循环之前，您正在创建 one 实例并将 same 实例附加到 allCard 数组。如果 Card 是 class（引用语义）该实例的所有出现都包含相同的数据（最后一个循环项）。

将两行放入重复循环中。

//Write the updateJSONCards method here:
func updateJSONCards(json: JSON) {
    //create the cards
     for (set, value) in json {
         if !json[set].isEmpty {
            for i in 0..<json[set].count {
                let card = Card()
                card.cardsSet = set
                card.name = json[set][i]["name"].stringValue
                allCard.append(card)
             }
         }
         else {
             print("The set \(set) has no cards")
         }
     }
  }

for loop cycle 始终显示 HTTP 请求后的最后一个数组值 swift 3

for loop cycle showing always the last array value swift 3 after HTTP request

asynchronous

httprequest

grand-central-dispatch

swift