如何在Swift中显示来自JSON的特定数据？

Question

嘿家伙我试图开发一个简单的应用程序，从雅虎财经获取数据。现在我可以从雅虎那里得到JSON响应，但我只需要一个来自它的股票公司名称的数据。那么我怎么能做到这一点？

我的代码：

import UIKit 

class ViewController: UIViewController, NSURLConnectionDelegate { 

lazy var data = NSMutableData() 

override func viewDidLoad() { 
    super.viewDidLoad() 
    startConnection() 
} 

    func startConnection(){ 
    var baseUrl:NSURL = NSURL(string:"http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20yahoo.finance.quotes%20where%20symbol%20in%20(%22PETR4.SA%22)&format=json&diagnostics=true&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys&callback=")! 
    var request: NSURLRequest = NSURLRequest(URL: baseUrl) 
    var connection: NSURLConnection = NSURLConnection(request: request, delegate: self, startImmediately: true)! 

} 

func connection(didReceiveResponse: NSURLConnection!, didReceiveResponse response: NSURLResponse!) { 

    // Recieved a new request, clear out the data object 
    self.data = NSMutableData() 

} 

func connection(connection: NSURLConnection!, didReceiveData data: NSData!) { 
    // Append the recieved chunk of data to our data object 
    self.data.appendData(data) 
} 



func connectionDidFinishLoading(connection: NSURLConnection!) { 
    // Request complete, self.data should now hold the resulting info 
    // Convert the retrieved data in to an object through JSON deserialization 

    var err: NSError 
    var jsonResult: NSDictionary = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSDictionary 

    println(jsonResult) 
} 
} 

响应：

{ 
query =  { 
    count = 1; 
    created = "2015-01-17T04:34:11Z"; 
    diagnostics =   { 
     "build-version" = "0.2.212"; 
     cache =    { 
      content = 5d1e1de680846a307c9874dc3d6878dc; 
      "execution-start-time" = 4; 
      "execution-stop-time" = 5; 
      "execution-time" = 1; 
      method = GET; 
      type = MEMCACHED; 
     }; 
     javascript =    { 
      "execution-start-time" = 3; 
      "execution-stop-time" = 104; 
      "execution-time" = 101; 
      "instructions-used" = 66631; 
      "table-name" = "yahoo.finance.quotes"; 
     }; 
     publiclyCallable = true; 
     query =    { 
      content = "select * from csv where url=@url and columns='Ask,AverageDailyVolume,Bid,AskRealtime,BidRealtime,BookValue,Change&PercentChange,Change,Commission,Currency,ChangeRealtime,AfterHoursChangeRealtime,DividendShare,LastTradeDate,TradeDate,EarningsShare,ErrorIndicationreturnedforsymbolchangedinvalid,EPSEstimateCurrentYear,EPSEstimateNextYear,EPSEstimateNextQuarter,DaysLow,DaysHigh,YearLow,YearHigh,HoldingsGainPercent,AnnualizedGain,HoldingsGain,HoldingsGainPercentRealtime,HoldingsGainRealtime,MoreInfo,OrderBookRealtime,MarketCapitalization,MarketCapRealtime,EBITDA,ChangeFromYearLow,PercentChangeFromYearLow,LastTradeRealtimeWithTime,ChangePercentRealtime,ChangeFromYearHigh,PercebtChangeFromYearHigh,LastTradeWithTime,LastTradePriceOnly,HighLimit,LowLimit,DaysRange,DaysRangeRealtime,FiftydayMovingAverage,TwoHundreddayMovingAverage,ChangeFromTwoHundreddayMovingAverage,PercentChangeFromTwoHundreddayMovingAverage,ChangeFromFiftydayMovingAverage,PercentChangeFromFiftydayMovingAverage,Name,Notes,Open,PreviousClose,PricePaid,ChangeinPercent,PriceSales,PriceBook,ExDividendDate,PERatio,DividendPayDate,PERatioRealtime,PEGRatio,PriceEPSEstimateCurrentYear,PriceEPSEstimateNextYear,Symbol,SharesOwned,ShortRatio,LastTradeTime,TickerTrend,OneyrTargetPrice,Volume,HoldingsValue,HoldingsValueRealtime,YearRange,DaysValueChange,DaysValueChangeRealtime,StockExchange,DividendYield'"; 
      "execution-start-time" = 5; 
      "execution-stop-time" = 95; 
      "execution-time" = 90; 
      params = "{url=[http://download.finance.yahoo.com/d/quotes.csv?f=aa2bb2b3b4cc1c3c4c6c8dd1d2ee1e7e8e9ghjkg1g3g4g5g6ii5j1j3j4j5j6k1k2k4k5ll1l2l3mm2m3m4m5m6m7m8nn4opp1p2p5p6qrr1r2r5r6r7ss1s7t1t7t8vv1v7ww1w4xy&s=PETR4.SA]}"; 
     }; 
     "service-time" = 91; 
     url =    (
          { 
       content = "http://www.datatables.org/yahoo/finance/yahoo.finance.quotes.xml"; 
       "execution-start-time" = 1; 
       "execution-stop-time" = 1; 
       "execution-time" = 0; 
      }, 
          { 
       content = "http://download.finance.yahoo.com/d/quotes.csv?f=aa2bb2b3b4cc1c3c4c6c8dd1d2ee1e7e8e9ghjkg1g3g4g5g6ii5j1j3j4j5j6k1k2k4k5ll1l2l3mm2m3m4m5m6m7m8nn4opp1p2p5p6qrr1r2r5r6r7ss1s7t1t7t8vv1v7ww1w4xy&s=PETR4.SA"; 
       "execution-start-time" = 5; 
       "execution-stop-time" = 95; 
       "execution-time" = 90; 
      } 
     ); 
     "user-time" = 106; 
    }; 
    lang = "en-us"; 
    results =   { 
     quote =    { 
      AfterHoursChangeRealtime = "N/A - N/A"; 
      AnnualizedGain = "<null>"; 
      Ask = "9.45"; 
      AskRealtime = "9.45"; 
      AverageDailyVolume = 80999600; 
      Bid = "9.44"; 
      BidRealtime = "9.44"; 
      BookValue = "27.652"; 
      Change = "+0.10"; 
      ChangeFromFiftydayMovingAverage = "-0.9209"; 
      ChangeFromTwoHundreddayMovingAverage = "-7.3725"; 
      ChangeFromYearHigh = "-15.46"; 
      ChangeFromYearLow = "+1.40"; 
      ChangePercentRealtime = "N/A - +1.07%"; 
      ChangeRealtime = "+0.10"; 
      "Change_PercentChange" = "+0.10 - +1.07%"; 
      ChangeinPercent = "+1.07%"; 
      Commission = "<null>"; 
      Currency = BRL; 
      DaysHigh = "9.63"; 
      DaysLow = "9.24"; 
      DaysRange = "9.24 - 9.63"; 
      DaysRangeRealtime = "N/A - N/A"; 
      DaysValueChange = "- - +1.07%"; 
      DaysValueChangeRealtime = "N/A - N/A"; 
      DividendPayDate = "<null>"; 
      DividendShare = "0.9672"; 
      DividendYield = "10.36"; 
      EBITDA = "66.171B"; 
      EPSEstimateCurrentYear = "0.00"; 
      EPSEstimateNextQuarter = "0.00"; 
      EPSEstimateNextYear = "0.00"; 
      EarningsShare = "1.535"; 
      ErrorIndicationreturnedforsymbolchangedinvalid = "<null>"; 
      ExDividendDate = "3-Apr-14"; 
      FiftydayMovingAverage = "10.3609"; 
      HighLimit = "<null>"; 
      HoldingsGain = "<null>"; 
      HoldingsGainPercent = "- - -"; 
      HoldingsGainPercentRealtime = "N/A - N/A"; 
      HoldingsGainRealtime = "<null>"; 
      HoldingsValue = "<null>"; 
      HoldingsValueRealtime = "<null>"; 
      LastTradeDate = "1/16/2015"; 
      LastTradePriceOnly = "9.44"; 
      LastTradeRealtimeWithTime = "N/A - <b>9.44</b>"; 
      LastTradeTime = "2:08pm"; 
      LastTradeWithTime = "Jan 16 - <b>9.44</b>"; 
      LowLimit = "<null>"; 
      MarketCapRealtime = "<null>"; 
      MarketCapitalization = "123.1B"; 
      MoreInfo = cnpI; 
      Name = "PETROBRAS -PN"; 
      Notes = "<null>"; 
      OneyrTargetPrice = "<null>"; 
      Open = "9.46"; 
      OrderBookRealtime = "<null>"; 
      PEGRatio = "<null>"; 
      PERatio = "6.08"; 
      PERatioRealtime = "<null>"; 
      PercebtChangeFromYearHigh = "-62.09%"; 
      PercentChange = "+1.07%"; 
      PercentChangeFromFiftydayMovingAverage = "-8.89%"; 
      PercentChangeFromTwoHundreddayMovingAverage = "-43.85%"; 
      PercentChangeFromYearLow = "+17.41%"; 
      PreviousClose = "9.34"; 
      PriceBook = "0.34"; 
      PriceEPSEstimateCurrentYear = "<null>"; 
      PriceEPSEstimateNextYear = "<null>"; 
      PricePaid = "<null>"; 
      PriceSales = "0.38"; 
      SharesOwned = "<null>"; 
      ShortRatio = "<null>"; 
      StockExchange = "Sao Paolo"; 
      Symbol = "PETR4.SA"; 
      TickerTrend = "&nbsp;======&nbsp;"; 
      TradeDate = "<null>"; 
      TwoHundreddayMovingAverage = "16.8125"; 
      Volume = 56271000; 
      YearHigh = "24.90"; 
      YearLow = "8.04"; 
      YearRange = "8.04 - 24.90"; 
      symbol = "PETR4.SA"; 
     }; 
    }; 
}; 
} 

Answer 1

的对象你得到NSJSONSerialization背面是一个标准的NSDictionary，你可以操纵它是这样。因此，要获得该公司的名称，你需要得到：

• 得到
• 得到了“结果”字典从查询字典
• 由NSJSONSerialization返回的对象“查询”词典获得了“引用“字典
• 最后，从引用字典中获取名称对象。

您可以使用此代码：

var query: NSDictionary = jsonResult["query"] as NSDictionary 
var results: NSDictionary = query["results"] as NSDictionary 
var quote: NSDictionary = results["quote"] as NSDictionary 
var companyName: String = quote["Name"] as String 
println(companyName)