ios 在 Swift 中从 JSON 数组中获取值
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Getting Values from JSON Array in Swift
提问by DookieMan
I'm trying to retrieve values from an array that I get from a JSON web request. But I can't get the valueForKey function to work so I can apply the String to a label. The example below searches Apples API for software. As a test, I want to be able to apply the "trackName" key to a UILabel, but everything I try, I either crash, or return nil.
我正在尝试从从 JSON Web 请求获得的数组中检索值。但是我无法让 valueForKey 函数工作，所以我可以将字符串应用于标签。下面的示例在 Apples API 中搜索软件。作为测试，我希望能够将“trackName”键应用于 UILabel，但是我尝试的所有操作，要么崩溃，要么返回 nil。
Here is my code
这是我的代码
func searchFunction(searchQuery: NSString) {
var url : NSURL = NSURL.URLWithString("https://itunes.apple.com/search?term=\(searchQuery)&media=software")
var request: NSURLRequest = NSURLRequest(URL:url)
let config = NSURLSessionConfiguration.defaultSessionConfiguration()
let session = NSURLSession(configuration: config)
let task : NSURLSessionDataTask = session.dataTaskWithRequest(request, completionHandler: {(data, response, error) in
var newdata : NSDictionary = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSDictionary
var info : NSArray = newdata.valueForKey("results") as NSArray
var name: String? = info.valueForKey("trackName") as? String // Returns nil
println(name)//Returns nil
var name2 : NSString = info.valueForKey("trackName") as NSString //Crashes
println(name2) //Crashes
});
task.resume()
println("Resumed")
}
The comments next to the variables explains what happens with each one. Can someone explain how I can convert the valueForKey("trackName") to a string that can be applied to a label?
变量旁边的注释解释了每个变量会发生什么。有人可以解释我如何将 valueForKey("trackName") 转换为可以应用于标签的字符串吗？
Thank you!
谢谢！
回答by Midhun MP
Info is an array, so check with:
Info 是一个数组，因此请检查：
var name: String? = info[0].valueForKey("trackName") as? String
var name: String? = info[0].valueForKey("trackName") as? NSString
