resignFirstResponder() 不适用于日期选择器

Question

我有一个用 Swift 5 编写的非常简单的CustomIDatePicker 类，它的顶部有一个工具栏，其中包含一个“完成”按钮。问题是，按下此按钮时键盘从未缩回。我已经尝试了 4 种不同的方法，请参阅下面的详细信息：

import UIKit

class CustomDatePicker: UIDatePicker {

    var zTextField: UITextField!

    let toolbar = UIToolbar()

    convenience init(textField: UITextField) {
        self.init()

        // bar buttons
        let doneBtn = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(donePressed(sender:)))

        toolbar.sizeToFit()
        toolbar.setItems([doneBtn], animated: true)

        self.datePickerMode = .date

        // link up the Text Field
        zTextField = textField
        zTextField.inputAccessoryView = toolbar
        zTextField.inputView = self
    }

    @objc func donePressed (sender: UIBarButtonItem) {
        print("done pressed") // this line appeared in the debugger

        //self.resignFirstResponder()
        //self.inputView?.resignFirstResponder()
        //self.endEditing(true)
        self.inputView?.endEditing(true) // tried all of these 4, but keyboard always remained in view
    }
}

一个非常简单的 ViewController 来测试这个类：

class ViewController: UIViewController {

    @IBOutlet weak var theTextField: UITextField!

    override func viewDidLoad() {
        super.viewDidLoad()

        let datePicker = CustomDatePicker(textField: theTextField)
    }
}

任何帮助将不胜感激！

Answer 1

实现 UITextField 委托函数

func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
  return false
}
@objc func donePressed (sender: UIBarButtonItem) {
        print("done pressed") 

        self.zTextField.resignFirstResponder() // new line
    }