单击UIButton以显示UIPickerView并选择按钮标题上的ID：Swift

Question

我的场景，我正在尝试创建按钮单击以打开UIPickerView并选择使用swift在按钮标题上显示的选择器数据。在这里，Toolbar我也想加入pickerview控制器。

 let button = UIButton(type: .custom)
  button.setTitle("",for: .normal)
  button.frame = CGRect(x: CGFloat(amount_textfield.frame.size.width - 9), y: CGFloat(5), width: CGFloat(9), height: CGFloat(20))
  button.addTarget(self, action: #selector(self.refresh), for: .touchUpInside)
  amount_textfield.leftView = button
  amount_textfield.leftViewMode = .always

 @IBAction func refresh(_ sender: Any) {
    // Here, I need to execute picker view 
 }

Answer 1

您必须遵循以下几个步骤：

1. 创建最初隐藏的UIPickerView并设置其delegate和dataSource

   @IBOutlet weak var pickerView: UIPickerView!
   
   override func viewDidLoad() {
       super.viewDidLoad()
       pickerView.delegate = self
       pickerView.dataSource = self
   }

2. 拥有用于此选择器视图的数据源数组

   class ViewController: UIViewController {
       var array = [String]()
   }
   
   extension ViewController: UIPickerViewDelegate, UIPickerViewDataSource {
       func numberOfComponents(in pickerView: UIPickerView) -> Int {
           return 1
       }
       func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
           return array.count
       }
       func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
           return array[row]
       }
   }

3. 按下按钮时取消隐藏选择器视图 pickerView.isHidden = false
4. 整合选择器视图的委托方法pickerView(_:didSelectRow:inComponent:)。选择行时，将index的标题设置为索引处数据源数组中的元素row

   func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
       button.setTitle(array[row], for: .normal)
   }

5. 可选：隐藏选择器视图 pickerView.isHidden = true