reloadData（）使用Swift

Question

我是Swift和Xcode的初学者，我试图从获取TMDb API的API数据并将其显示在UITableView中。 我收到以下错误：

fatal error: unexpectedly found nil while unwrapping an Optional value 

的亮的行是：

self.nyheterTableView.reloadData() 

而且我对的viewController完整的代码是：

import UIKit 

class nyheterViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, APIControllerProtocol { 

    @IBOutlet weak var nyheterTableView: UITableView! 

    var searchResultsData: NSArray = [] 
    var api: APIController = APIController() 

    func JSONAPIResults(results: NSArray) { 
     dispatch_async(dispatch_get_main_queue(), { 
      self.searchResultsData = results 
      print(self.searchResultsData.count) // <- 20 
      self.nyheterTableView.reloadData() 
     }) 
    } 


    override func viewDidLoad() { 
     super.viewDidLoad() 

     //Construct the API URL that you want to call 
     var APIkey: String = "The deeper thought is, the taller it becomes." //Replace with your Api Key" 
     var APIBaseUrl: String = "http://api.themoviedb.org/3/movie/upcoming?api_key=" 
     var urlString:String = "\(APIBaseUrl)" + "\(APIkey)" 

     //Call the API by using the delegate and passing the API url 
     self.api.delegate = self 
     api.GetAPIResultsAsync(urlString) 
    } 

    override func didReceiveMemoryWarning() { 
     super.didReceiveMemoryWarning() 
     // Dispose of any resources that can be recreated. 
    } 

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int { 
     print(self.searchResultsData.count) // <- 00 
     return searchResultsData.count 
    } 

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell { 
     let cellIdentifier: String = "nyheterResultsCell" 


     let cell: UITableViewCell = tableView.dequeueReusableCellWithIdentifier(cellIdentifier) as UITableViewCell 

     //Create a variable that will contain the result data array item for each row 
     var cellData: NSDictionary = self.searchResultsData[indexPath.row] as NSDictionary 
     //Assign and display the Title field 

     cell.textLabel?.text = cellData["original_title"] as? String 

     // Get the release date string for display in the subtitle 
     var releaseDate: String = cellData["release_date"] as String 

     cell.detailTextLabel?.text = releaseDate 

     return cell 
    } 
} 

为APIController完整代码：

import UIKit 

protocol APIControllerProtocol { 
    func JSONAPIResults(results: NSArray) 

} 

class APIController: NSObject { 
    var delegate:APIControllerProtocol? 

    func GetAPIResultsAsync(urlString:String) { 

     //The Url that will be called 
     var url = NSURL.URLWithString(urlString) 
     //Create a request 
     var request: NSURLRequest = NSURLRequest(URL: url) 
     //Create a queue to hold the call 
     var queue: NSOperationQueue = NSOperationQueue() 

     // Sending Asynchronous request using NSURLConnection 
     NSURLConnection.sendAsynchronousRequest(request, queue: queue, completionHandler:{(response:NSURLResponse!, responseData:NSData!, error: NSError!) ->Void in 
      var error: AutoreleasingUnsafeMutablePointer<NSError?> = nil 
      //Serialize the JSON result into a dictionary 
      let jsonResult: NSDictionary! = NSJSONSerialization.JSONObjectWithData(responseData, options:NSJSONReadingOptions.MutableContainers, error: error) as? NSDictionary 

      //If there is a result add the data into an array 
      if jsonResult.count>0 && jsonResult["results"]?.count > 0 { 

       var results: NSArray = jsonResult["results"] as NSArray 
       //Use the completion handler to pass the results 
       self.delegate?.JSONAPIResults(results) 

      } else { 

       println(error) 
      } 
     }) 
    } 
} 

我相信问题发生在reloadData()，因为在重新加载行计数为20和以后时，它返回的函数是00.或者它发生在APIController中，它不完全理解。 我一直在关注以下指南：http://www.sitepoint.com/introduction-swift-programming-language/（向下3/4页）

如上所述，我是Swift初学者，Xcode和原生iOS编程，非常感谢。

干杯。

Answer 1

您的@IBOutlet对于您的UITableView未正确连接。在你的宣言结束

@IBOutlet weak var nyheterTableView: UITableView! 

注意!：

仔细检查在Interface Builder您的网点，并确保nyheterTableView已连接。这是正确的，你如何定义你的网点。但是，这也有点危险，因为它允许您使用nyheterTableView而不必检查以确保它不是nil。这称为“隐式解包可选”，在这种情况下用作方便您 - 所以在使用它们之前，您不必使用if let检查所有。这很好，假设你正确连接你的插座。