如何在 PickerView 首次弹出时/用户尚未开始任何访问时从中获取第一个值

Question

我尝试使用这种方法selectedRow(inComponent: 0)，但它对我不起作用。有什么办法可以在选择器不活动时从选择器中获取 first/default 值？

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return countries.count
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
    return countries[row].name
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
       country.text = countries[row].name //`country.text` is just textField
    }
}

Answer 1

没什么大不了的-

只需将您的选择器视图定义为全局视图并访问 objectAtIndex(0)

的值

并将这行代码写在viewDidLoad()

不准确，大概是这样-

@IBOutlet var yourPicker: UIPickerView! = UIPickerView()

var yourArray = ["Apple", "Samsung", "Nokia"]


override func viewDidLoad() {
    super.viewDidLoad()
    yourPicker.text = yourArray[0]
}

如何在 PickerView 首次弹出时/用户尚未开始任何访问时从中获取第一个值

How to get the very first value from PickerView when it first pop up / when user not yet start any access

swift

getvalue

pickerview