Swift中的pickerView不显示数据

Question

这似乎太简单了，不足以作为一个帖子，但我一直坚持这个问题的时间超过了我想要的时间。 pickerView不显示数组[durations]。运行时，模拟器只是空字段。代码是直接从UI类复制的，但似乎缺少某些东西。

class FirstViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
    @IBOutlet weak var durationPicker: UIPickerView!
    var durations = ["72 hours", "24 hours", "6 hours", "2 hours", "20 minutes"]
    var durationsValue = [72.0, 24.0, 6.0, 2.0, 0.329]
    var itemSelected: String = ""
    var selectedDuration: Double = 0.0

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

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

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

    func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return 5
    }

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

    func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        itemSelected = durations[row]
        selectedDuration = durationsValue[row]
    }
}

Answer 1

你需要在delegate中设置datasource和viewDidLoad()

durationPicker.delegate = self
durationPicker.dataSource = self

或者使用Xcode界面连接您的选择器delegate和datasource

Answer 2

我建议看这个视频。这位女士在解释各种iOS相关主题方面表现出色。

https://www.youtube.com/watch?v=MdXmIViD17U

跳出来的问题是你在顶部指定了数组。您应该使用return yourArray.count返回Ints，而不是硬编码值。