从 NSDictionary 获取 JSON 数据

Question

我的 api

中有结构

{
    "Hall":"Hall",
    "Date":20180501,
    "Prices":[
        {
            "Time":1,
            "Price":4000
        },
        {
            "Time":2,
            "Price":4000
        },
        {
            "Time":3,
            "Price":4000
        }
    ]
}

现在卡住了，拉不出价格和时间。我明白了很多问题，但我还是不明白，请帮助。

我使用这个代码：

let url = URL(string: "http://<...>/api/prices?hall=<...>&date=20180501")

    var request = URLRequest(url: url!)

    request.httpMethod = "GET" 

    let task = URLSession.shared.dataTask(with: request, completionHandler: { (data, response, error) in

        if let err = error {
            print(err)
        } else {

            do {

                if let jsonResult = try JSONSerialization.jsonObject(with: data!, options: []) as? NSDictionary {

                    // ... 

                }

                DispatchQueue.main.async {
                    self.collectionView.reloadData()
                }

            } catch {
                print("error")
            }
        }
    })
    task.resume()
}

我是 json 的新手，刚开始学习它。我知道这很容易，但我想不通。我也知道我可以使用 codable 和 decodable，但现在我需要在这个实现中获得价格和时间。

Answer 1

产品结构：

struct Product{
    
    let time:Int
    let price:Int
    
    init(_ object:[String:Int]){
        
        self.time = object["Time"] ?? 0
        self.price = object["Price"] ?? 0
    }
}

Class变量：

var products = [Product]()

JSON 解析：

do{
    
    if let jsonObject = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [String:Any] {
        
        //Use Swift dictionary instead of NSDictionary

        if let prices = jsonObject["Prices"] as? [[String:Int]]{
            
            for price in prices{
                
                self.products.append(Product(price))
            }
        }
    }
    
}catch{
    print("Error: ",error.localizedDescription)
}

现在，您的 products Array 将包含所有 Price 和 Time

示例：

for product in products{
    
    print("Time:",product.time)
    print("Price:",product.price)
}

输出：

Time: 1

Price: 4000

Time: 2

Price: 4000

Time: 3

Price: 4000

注意：为了更好的理解，这是我的video系列关于JSON在swift解析4

Answer 2

    var timeArray = [String]()
    var priceArray = [String]()
    if  jsonResult.object(forKey:"Prices") as? NSArray != nil
    {
        let pricesArray = jsonResult.object(forKey:"Prices") as! NSArray
        for i in 0..<self.pricesArray.count
        {
            // Getting Time
            if jsonResult.object(forKey:"Time") as? Int != nil
            {
                self.timeArray.append(jsonResult.object(forKey:"Time") as! Int)
            }
            else
            {
                print("Time is not a intrger")
            }
            // Getting Price
            if jsonResult.object(forKey:"Price") as? Int != nil
            {
                self.priceArray.append(jsonResult.object(forKey:"Price") as! Int)
            }
            else
            {
                print("Price is not a intrger")
            }
        }
    }
    else
    {
        print("Empty Array")
    }

Answer 3

首先不要使用NSArray / NSDictionary，使用原生Swift类型。

键 Prices 的值是 [String:Int] 个字典的数组：

if let jsonResult = try JSONSerialization.jsonObject(with: data!) as? [String:Any], 
   let prices = jsonResult["Prices"] as? [[String:Int]] {
    for price in prices {
        print(price["Time"]!, price["Price"]!)
    }
}

但是我建议将 JSON 解码成一个在 Swift 4

中非常简单的结构

struct Item : Decodable {
    let hall : String
    let date : Int
    let prices : [Price]

    private enum CodingKeys : String, CodingKey { case hall = "Hall",  date = "Date", prices = "Prices"}
}

struct Price  : Decodable {
    let time, price : Int

    private enum CodingKeys : String, CodingKey { case time = "Time",  price = "Price"}
}

do {
    let result = try JSONDecoder().decode(Item.self, from: data!)
    print(result)
} catch { print(error) }

Answer 4

if let json = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [String:Any], let pirces = json["prices"] // checking json is formed well.
{
 for price in prices { // iterating throught array that you received. 
    print (price["Price"])
  }
}

从 NSDictionary 获取 JSON 数据

Get JSON data from NSDictionary

xcode

json

nsdictionary

ios

swift