ios - Swift - UIPickerView - 使用 "reloadAllComponents"后组件仍然隐藏

Question

我正在使用网络服务来更新 uipickerview 的组件。

将所有组件附加到 pickCityOptions 数组后，我调用“reloadAllComponents”来更新 uipickerview。

我非常适合更新组件，但更新所有组件后仍然隐藏，直到我在选择器上选项卡，然后所有组件都会出现。

@IBOutlet weak var pickCity: UIPickerView!

let defaults = NSUserDefaults.standardUserDefaults()

var pickCityOptions = [String]()
var items = [[String:String]()]


override func viewDidLoad() {
    super.viewDidLoad()

    self.pickCity.dataSource = self;
    self.pickCity.delegate = self;

    let urlPath = "http://www.waelmoharram.com/dalel/api/v1/cities"

    let url = NSURL(string: urlPath)

    let session = NSURLSession.sharedSession()

    let task = session.dataTaskWithURL(url!, completionHandler: {data, response, error -> Void in

        if error != nil {

            print(error)

        } else {


            do {
                let jsonResult = try NSJSONSerialization.JSONObjectWithData(data!, options:NSJSONReadingOptions.MutableContainers ) as! NSArray


                var item:AnyObject

                for i in 0 ... jsonResult.count - 1 {

                    self.items.append([String:String]())

                    item = jsonResult[i]



                    self.items[i]["id"] = "\(item["id"]!)" as NSString as String

                    self.items[i]["city_name"] = item["city_name"] as! NSString as String



                    self.pickCityOptions.append(self.items[i]["city_name"]!)

                }

                self.pickCity.reloadAllComponents()



            } catch {

                print(error)

            }


        }

    })

    task.resume()

    if let currentCityRow = self.defaults.stringForKey("city") {

        self.pickCity.selectRow(Int(currentCityRow)!, inComponent: 0, animated: true)

    }else{

        self.pickCity.selectRow(0, inComponent: 0, animated: true)

    }

}

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

func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
{
    defaults.setObject(row, forKey: "city")

}


func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
    return 1
}

func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return pickCityOptions.count;
}

func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
    return pickCityOptions[row]
}

Answer 1

您需要将 pickCityOptions 用作 NSMutableArray。不要使用 pickCityOptions.append 而是使用 pickCityOptions.addObject

    var pickCityOptions = NSMutableArray()
    pickCityOptions.addObject(self.items[i]["city_name"]!)