使 UIPickerView 旋转

Question

有没有办法让 UIPickerView 像彩票一样“旋转”。我想做一个 UIPickerView 和一个按钮。当用户按下按钮时，我希望 UIPickerView 旋转一会儿，然后停在随机位置。这可能吗？

Answer 1

我想你正在寻找这个：

pick.selectRow(10, inComponent: 0, animated: true)

但是，如果您想查看我为您制作的完整示例。

class ViewController: UIViewController, UIPickerViewDataSource{

@IBOutlet var pick: UIPickerView!

var myArr = [Int]()

var myT = Timer()

override func viewDidLoad() {
    super.viewDidLoad()

    for element in 0...100 {

        myArr.append(element)
        }


    myT = Timer.scheduledTimer(timeInterval: 3, target: self, selector: #selector(ViewController.movePicker), userInfo: nil, repeats: true)



}



 //MARK: - move picker

func movePicker()  {


    let position = Int(arc4random_uniform(89) + 10)


    pick.selectRow(position, inComponent: 0, animated: true)
    pick.showsSelectionIndicator = true

    if position == 50 || position == 72 || position == 90 || position == 35  {

        myT.invalidate()

        let alert = UIAlertController(title: "You Won!!", message: "Congratulations!!!", preferredStyle: .alert)
        let buttonOK = UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: nil)
        let playAgain = UIAlertAction(title: "Play Again!", style: .default, handler: { (action) in

            self.myT = Timer.scheduledTimer(timeInterval: 3, target: self, selector: #selector(ViewController.movePicker), userInfo: nil, repeats: true)
        })

        alert.addAction(buttonOK)
        alert.addAction(playAgain)

        present(alert, animated: true, completion: nil)



    }

}




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

    return 1

}

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

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


}

希望对你有帮助