如何将选择器视图设置在选择列表的中间？

Question

我已经像上图那样设置了一个picker view，可以看到，在view controller出现后的起点处，selection会自动显示列表中的第一个字符串（London）。但我希望当视图第一次出现时，它会显示列表中间的字符串选择，如下图

这是我使用的代码

class ViewController: UIViewController,UIPickerViewDelegate,UIPickerViewDataSource {

    @IBOutlet weak var cityLabel: UILabel!
    @IBOutlet weak var cityPicker: UIPickerView!

    let city = ["London","New York","Tokyo","Kuala Lumpur","Bali","Manchester","Madrid"]

    override func viewDidLoad() {
        super.viewDidLoad()

        // UIPickerView Delegate dan Datasource sebagai self sudah dilakukan melalui interface builder dengan mendrag ke tombol lingkaran kuning dari pickerview nya
        cityLabel.text = city[6]
    }

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

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

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

    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        cityLabel.text = city[row]
    }
}

我应该怎么做才能做到这一点？

Answer 1

Select 你想要的行在 viewDidLoad:

override func viewDidLoad() {
    super.viewDidLoad()
    cityPicker.selectRow(3, inComponent: 0, animated: false)
    cityLabel.text = city[cityPicker.selectedRow(inComponent:0)]
}

如何将选择器视图设置在选择列表的中间？

how to set picker view to be in the middle of selection list?

uipickerview

ios

swift