table view not displaying contents in the cells

Question

I am trying to fetch some data from stack exchange api using alamofire and swifty json. I am able to print the required data in the log, but when i run the app the simulator shows only empty cells. I checked the identifier and i have set the prototype cell value to 1.`

class MainTableViewController: UITableViewController,UISearchResultsUpdating {


    var searchKeyword: String = "questions"

    // empty array to store the search results
    var searchResults: [SearchResult] = []

func alamofireFunction() {
  Alamofire.request(.GET, "https://api.stackexchange.com/2.2/questions?=%20\(searchKeyword)%20viewpage=1&fromdate=1183075200&todate=2554416000&order=asc&sort=activity&tagged=ios&site=stackoverflow").responseJSON { (response) -> Void in

            switch response.result {

            case .Success:
                if let value = response.result.value {
                    let json = JSON(value)
                    for (var idx=0; idx<=json["items"].count; idx++) {
                        let result = SearchResult()
                        //print(json["items"][idx]["title"].stringValue)
                        result.name = json["items"][idx]["owner"]["display_name"].stringValue
                        result.question = json["items"][idx]["title"].stringValue
                        result.image = json["items"][idx]["owner"]["profile_image"].stringValue
                        self.searchResults.append(result)     
                    }                   
                }

            case .Failure:
                print("error")



            }
        }


    }


    override func viewDidLoad() {
        super.viewDidLoad()


        alamofireFunction()

 }
         override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }   
    // MARK: - Table view data source
    override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! MainTableViewCell


        cell.questionLabel.text = searchResults[indexPath.row].question
      cell.nameLabel.text = searchResults[indexPath.row].name


        return cell
    }



        override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
            // #warning Incomplete implementation, return the number of sections
            return 1
        }

        override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
            // #warning Incomplete implementation, return the number of rows
            return searchResults.count

    }`

Answer 1

You must call self.reloadData() when your data source changes. This will cause tableView to call dataSource methods.

Answer 2

这是因为您使用的是来自Url的请求，该过程在线程上执行，因此当您以这种方式获取数据时，必须调用tableView.reloadData()来告知数据源该过程已完成。