[iOS - Swift] UIPickerView

透過滾動提供使用者選擇的一種View，必須實作UIPickerDataSource與UIPickerViewDelegate兩個Protocol才可使用，

extension ViewController: UIPickerViewDataSource {

    

    ///總共有幾個Component

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

        return 2

    }

    

    ///每個Component有幾個Row

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {

        return 3

    }

        

}

extension ViewController: UIPickerViewDelegate {

    ///所顯示的Title

    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {

        return "\(component), \(row)"

    }

}

最後別忘了指定成self

pickerView.dataSource = self

pickerView.delegate = self

你可以透過此函式來得知使用者是選擇哪一個Row

 pickerView.selectedRow(inComponent: 0) //第0個Component選擇了第幾個Row