Error Domain=NSCocoaErrorDomain Code=3840“无值。”UserInfo={NSDebugDescription=无值。}

Question

我正在学习JSON。我在从URL解析JSON时遇到问题。错误是“Error Domain=NSCocoaErrorDomain Code=3840”无值。“UserInfo={NSDebugDescription=无值。}”

JSON是有效的-我已经检查过了。这是JSON的结构：

[{"id":33,"name":"5","sort":2},{"id":34,"name":"6","sort":3},{"id":35,"name":"7","sortOrder":4}]

这是我的代码：导入UIKit

class ViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()


    let urlAsString = "http://www.url.address/"
    let url = NSURL(string: urlAsString)!
    let urlSession = NSURLSession.sharedSession()
    let username = "admin"
    let password = "admin"

    struct Address {

        let name: String?
        let id: String?
        let sortOrder: String?

        init(dict: [String: AnyObject]) {

            name = dict["name"] as? String
            id = dict["id"] as? String
            sortOrder = dict["sort"] as? String
        }
    }
    let path = NSBundle.mainBundle().pathForResource("sections", ofType: "json")
    let jsonData = NSData()

    do {
        if let jsonDic = try NSJSONSerialization.JSONObjectWithData(jsonData,
            options: .MutableContainers) as? [String: AnyObject] {

                let addr = Address(dict: jsonDic)                    
                print("jsonDic")
        }

        } catch let error as NSError {
            print(error)
        }
}
func backButton(sender: AnyObject) {
    self.dismissViewControllerAnimated(true, completion: {})
}

}

Answer 1

您需要实际使用文件中的数据：

保护let path=NSBundle.mainBundle（）. path ForResource（"区段"， ofType："json"）， let jsonData=NSData（content sOfFile： path）否则{FatalError（"无法在主包中找到或加载区段文件"）}做{如果让区段=尝试NSJSONSerialization.JSONObjectWithData（jsonData，选项：. MutableContainers）作为？[String： AnyObject] { // 与区段一起工作}…