【发布时间】：2021-03-02 16:58:25
【问题描述】：
我目前正在使用 XCode 版本 11.3.1 (11C505) 和 Swift 5，我似乎无法找到关于如何从选择轮（视图）中获取所选值的好答案。这是我ViewController.swift的相关代码
class ViewController: UIViewController {
@IBOutlet weak var numberPicker: UIPickerView!
@IBOutlet weak var test: UILabel!
private let possibleNums: [Int] = Array(1...16) // Create an array of Ints from 1 to 16
override func viewDidLoad() {
super.viewDidLoad()
numberPicker.dataSource = self
numberPicker.delegate = self
}
}
extension ViewController: UIPickerViewDataSource {
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return possibleNums.count
}
// Attempt at getting the selected value, didn't work
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int {
print(possibleNums[numberPicker.selectedRow(inComponent: 0)])
test.text = "\(possibleNums[numberPicker.selectedRow(inComponent: 0)])"
}
}
extension ViewController: UIPickerViewDelegate {
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return String(possibleNums[row])
}
}
编辑：解决方案也在 cmets 中，所以我想我会把它放在这里以防其他人发现这个：
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int 应该是 func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int（缺少 _）
而test.text = "\(possibleNums[numberPicker.selectedRow(inComponent: 0)])" 应该只是test.text = "\test.text = "\(possibleNums[row])"
【问题讨论】：
-
我猜你的方法没有被调用？这很正常：
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int这不是文档中的那个。删除它，然后重写它，让自动补全帮助你，或者用正确的替换它，见developer.apple.com/documentation/uikit/uipickerviewdelegate/… -
见stackoverflow.com/a/49306695/1801544这是同一个问题。
-
@Larme 是的，最终在函数参数的开头缺少下划线（应该是
_ pickerView）