swift - Json 雅虎 API 错误

Question

我一直在开发一个使用雅虎财经的 json 获取股票数据的应用程序，但我在错误代码中遇到了问题。它在 else 语句中显示未解析的标识符 jsonDict 和预期的表达式错误。

这是代码。

import Foundation

let kNotificationStocksUpdated = "stocksUpdated"

class StockManagerSingleton {

//Singleton Init
class var sharedInstance : StockManagerSingleton {
    struct Static {
        static let instance : StockManagerSingleton = StockManagerSingleton()
    }
    return Static.instance
}

/*!
* @discussion Function that given an array of symbols, get their stock prizes from yahoo and send them inside a NSNotification UserInfo
* @param stocks An Array of tuples with the symbols in position 0 of each tuple
*/
func updateListOfSymbols(stocks:Array<(String,Double)>) ->() {

    //1: YAHOO Finance API: Request for a list of symbols example:
    //http://query.yahooapis.com/v1/public/yql?q=select * from yahoo.finance.quotes where symbol IN ("AAPL","GOOG","FB")&format=json&env=http://datatables.org/alltables.env

    //2: Build the URL as above with our array of symbols
    var stringQuotes = "(";
    for quoteTuple in stocks {
        stringQuotes = stringQuotes+"\""+quoteTuple.0+"\","
    }
    stringQuotes = stringQuotes.substringToIndex(stringQuotes.endIndex.predecessor())
    stringQuotes = stringQuotes + ")"

    let urlString:String = ("http://query.yahooapis.com/v1/public/yql?q=select * from yahoo.finance.quotes where symbol IN "+stringQuotes+"&format=json&env=http://datatables.org/alltables.env").stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding)!
    let url : NSURL = NSURL(string: urlString)!

    let request: NSURLRequest = NSURLRequest(URL:url)
    let config = NSURLSessionConfiguration.defaultSessionConfiguration()
    let session = NSURLSession(configuration: config)

    //3: Completion block/Clousure for the NSURLSessionDataTask
    let task : NSURLSessionDataTask = session.dataTaskWithRequest(request, completionHandler: {data, response, error -> Void in

        do {
            if let _ = try NSJSONSerialization.JSONObjectWithData(data!, options: .MutableContainers) as? NSDictionary {
                // Success block...
            }
        } catch {
            print(error)
        }

        else {
                //5: Extract the Quotes and Values and send them inside a NSNotification
                var quotes:NSArray = ((jsonDict.objectForKey("query") as NSDictionary).objectForKey("results") as NSDictionary).objectForKey("quote") as NSArray
                dispatch_async(dispatch_get_main_queue(), {
                    NSNotificationCenter.defaultCenter().postNotificationName(kNotificationStocksUpdated, object: nil, userInfo: [kNotificationStocksUpdated:quotes])
                })
            }
    })


    //6: DONT FORGET to LAUNCH the NSURLSessionDataTask!!!!!!
    task.resume()
}
}

有问题的代码行是。

var quotes:NSArray = ((jsonDict.objectForKey("query") as NSDictionary).objectForKey("results") as NSDictionary).objectForKey("quote") as NSArray

Answer 1

目前您有一些没有意义的代码。例如else没有对应的if。我不知道你想用你的代码做什么，但它看起来应该类似于下面的内容。请注意，这也会是错误的。您需要返回原始代码的来源，因为您当前的代码将永远无法工作。

func updateListOfSymbols(stocks:Array<(String,Double)>) ->() {

    //1: YAHOO Finance API: Request for a list of symbols example:
    //http://query.yahooapis.com/v1/public/yql?q=select * from yahoo.finance.quotes where symbol IN ("AAPL","GOOG","FB")&format=json&env=http://datatables.org/alltables.env

    //2: Build the URL as above with our array of symbols
    var stringQuotes = "(";
    for quoteTuple in stocks {
        stringQuotes = stringQuotes+"\""+quoteTuple.0+"\","
    }
    stringQuotes = stringQuotes.substringToIndex(stringQuotes.endIndex.predecessor())
    stringQuotes = stringQuotes + ")"

    let urlString:String = ("http://query.yahooapis.com/v1/public/yql?q=select * from yahoo.finance.quotes where symbol IN "+stringQuotes+"&format=json&env=http://datatables.org/alltables.env").stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding)!
    let url : NSURL = NSURL(string: urlString)!

    let request: NSURLRequest = NSURLRequest(URL:url)
    let config = NSURLSessionConfiguration.defaultSessionConfiguration()
    let session = NSURLSession(configuration: config)

    //3: Completion block/Clousure for the NSURLSessionDataTask
    let task : NSURLSessionDataTask = session.dataTaskWithRequest(request, completionHandler: {data, response, error -> Void in

        do {
            if let jsonDict = try NSJSONSerialization.JSONObjectWithData(data!, options: .MutableContainers) as? NSDictionary {
                // Success block...
                //5: Extract the Quotes and Values and send them inside a NSNotification
                var quotes:NSArray = ((jsonDict.objectForKey("query") as NSDictionary).objectForKey("results") as NSDictionary).objectForKey("quote") as NSArray
                dispatch_async(dispatch_get_main_queue(), {
                    NSNotificationCenter.defaultCenter().postNotificationName(kNotificationStocksUpdated, object: nil, userInfo: [kNotificationStocksUpdated:quotes])
                })
            }
        } catch {
            print(error)
        }

    })


    //6: DONT FORGET to LAUNCH the NSURLSessionDataTask!!!!!!
    task.resume()
}