Question

我的场景，我正在尝试创建按钮单击以打开UIPickerView并选择选择器数据以快速显示按钮标题。在这里，我还想将Toolbar添加到pickerview控制器中。

 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

您必须遵循的几个步骤：

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
}

具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]
    }
}

在按下按钮时取消隐藏选择器视图
```
pickerView.isHidden = false
```
集成选择器视图的委托方法pickerView(_:didSelectRow:inComponent:)。选择行后，将按钮的标题设置为数据源数组中元素的元素，位于选定的索引row
```
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    button.setTitle(array[row], for: .normal)
}
```
可选：隐藏选择器视图
```
pickerView.isHidden = true
```

单击UIButton以显示UIPickerView并在按钮标题上选择ID：Swift

1 个答案: