swift - 类型 'NSFastEnumerationIterator.Element' 没有下标成员

Question

我遇到了这个错误。

你能告诉我如何修复此代码以进行锻炼吗？

我们将不胜感激。

//这是JSON数据。

{  
   "boxOfficeResult":{  
      "boxofficeType":"일별 박스오피스",
      "showRange":"20161020~20161020",
      "dailyBoxOfficeList":[  
         {  
            "rnum":"1",
            "rank":"1",
            "rankInten":"0",
            "rankOldAndNew":"OLD",
            "movieCd":"20153444",
            "movieNm":"럭키",
            "openDt":"2016-10-13",
            "salesAmt":"1452501900",
            "salesShare":"60.2",
            "salesInten":"-85908900",
            "salesChange":"-10",
            "salesAcc":"23329189948",
            "audiCnt":"193801",
            "audiInten":"-11203",
            "audiChange":"-10",
            "audiAcc":"2879481",
            "scrnCnt":"968",
            "showCnt":"4961"
         }, ...

//这是代码。

var list = Array<MovieVO>()

override func viewDidLoad() {

    let apiURI = NSURL(string: "http://www.kobis.or.kr/kobisopenapi/webservice/rest/boxoffice/searchDailyBoxOfficeList.json?key=a7497a5e700fdff2f3fd468b604d9d18&targetDt=20161020")

    let apidata : NSData? = NSData(contentsOf: apiURI! as URL)

    NSLog("result = %@", NSString(data: apidata! as Data, encoding: String.Encoding.utf8.rawValue)!)


    do {
        let apiDictionary = try JSONSerialization.jsonObject(with: apidata! as Data, options: []) as! NSDictionary

        let boxOfficeResult = apiDictionary["boxOfficeResult"] as! NSDictionary
        let dailyBoxOfficeList = boxOfficeResult["dailyBoxOfficeList"] as! NSArray

        var mvo : MovieVO

        for row in dailyBoxOfficeList {
            mvo = MovieVO()

            mvo.rank = row["rank"] as? String  // error occur
            mvo.movieNm = row["movieNm"] as? String
            mvo.openDt = row["openDt"] as? String
            mvo.audiCnt = row["audiCnt"] as? String

            self.list.append(mvo)
        }

    } catch {

    }
}

Answer 1

最短的快速修复是改变这一行:

        let dailyBoxOfficeList = boxOfficeResult["dailyBoxOfficeList"] as! NSArray

像这样:

        let dailyBoxOfficeList = boxOfficeResult["dailyBoxOfficeList"] as! [[String: Any]]

在Swift 3中，NSArray的Element类型变成了Any，您不能对Any应用任何方法(包括下标)。在您的代码中，row 的类型被推断为 Any，您不能将下标应用于 row。

---

稍微超前一点，让您的代码更快捷、更安全:

enum MyError: Error {
    case badURL
    case notDictionary
    case invalidBoxOfficeResult
    case invalidDailyBoxOfficeList
}
override func viewDidLoad() {

    do {
        //Use `URL` rather than `NSURL`
        guard let apiURI = URL(string: "http://www.kobis.or.kr/kobisopenapi/webservice/rest/boxoffice/searchDailyBoxOfficeList.json?key=a7497a5e700fdff2f3fd468b604d9d18&targetDt=20161020") else {
            throw MyError.badURL
        }

        //Use `Data` rather than `NSData`
        //Avoid using forced unwrapping
        let apidata = try Data(contentsOf: apiURI)

        //Use `String` rather than `NSString`
        NSLog("result = %@", String(data: apidata, encoding: .utf8)!)

        //Cast the resutl of type `Any` as soon as possible
        guard let apiDictionary = try JSONSerialization.jsonObject(with: apidata) as? [String: Any] else {
            throw MyError.notDictionary
        }

        //Cast the resutl of type `Any` as soon as possible
        guard let boxOfficeResult = apiDictionary["boxOfficeResult"] as? [String: Any] else {
            throw MyError.invalidBoxOfficeResult
        }

        //Cast the resutl of type `Any` as soon as possible
        guard let dailyBoxOfficeList = boxOfficeResult["dailyBoxOfficeList"] as? [[String: String]] else {
            throw MyError.invalidDailyBoxOfficeList
        }

        for row in dailyBoxOfficeList {
            var mvo = MovieVO() //<- Assuming `MovieVO` is a struct, use `let` if it is a class

            mvo.rank = row["rank"]
            mvo.movieNm = row["movieNm"]
            mvo.openDt = row["openDt"]
            mvo.audiCnt = row["audiCnt"]

            self.list.append(mvo)
        }

    } catch {
        print(error) //<- You should not ignore errors
    }
}

---

还有一点……

Data(contentsOf:)(或 NSData(contentsOf:))可能会消耗不确定的时间并阻塞主线程，直到接收到整个数据。如果您正在为 App Store 编写应用程序，则此类应用程序有被拒绝的风险。尝试在后台线程中加载内容。