我的情况与这个问题完全相同：
UIDatePicker in UITextField in UITableView realtime update
总而言之：我在一个自定义单元格中有一个文本字段，它调用了UIDatePicker。我希望文本字段在修改日期选择器时更新，并且我希望它在点击“完成”按钮（位于为日期选择器创建的工具栏内）时存储最后一个值。
我可以在pickerview中获得所选的值（实际上我将其打印到控制台），但我不能将该值放入文本字段中。
但是，我需要用swift来做，而我做不到。我一直在尝试用行动：#selector（），但由于它在选择器内的函数中不接受超过1个参数，因此它对我没有帮助。
自定义表格视图单元格：

class employeesTableViewCell : UITableViewCell {
   @IBOutlet weak var employeeNumberField: UILabel!
   @IBOutlet weak var employeeNameField: UITextField!
   @IBOutlet weak var employeeSurnameField: UITextField!
   @IBOutlet weak var employeeIDField: UITextField!
   @IBOutlet weak var employeeBirthDateTxtFieldOutlet: UITextField!
}

在ViewController中（如下所示的标记策略用于捕获通过textFieldShouldReturn编辑的字段）：

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "employeeCell") as! employeesTableViewCell!

    createPickerView(sender:  (cell?.employeeBirthDateTxtFieldOutlet)!)
    createToolbar(sender:  (cell?.employeeBirthDateTxtFieldOutlet)!)

    cell?.employeeNameField.tag = indexPath.row * 10 + 1
    cell?.employeeSurnameField.tag = indexPath.row * 10 + 2
    cell?.employeeIDDocField.tag = indexPath.row * 10 + 3
    cell?.employeeBirthDateTxtFieldOutlet.tag = indexPath.row * 10 + 5
    cell?.employeeNumberField.text = "Employee \(indexPath.row + 1)"

    return cell!
}

func createPickerView(sender: UITextField){
    let datePickerView : UIDatePicker = UIDatePicker()

    datePickerView.datePickerMode = UIDatePickerMode.date
    sender.inputView = datePickerView
    datePickerView.tag = sender.tag
    datePickerView.addTarget(self, action: #selector(datePickerValueChanged(caller:destination:)), for: UIControlEvents.valueChanged)
}

@objc func datePickerValueChanged(caller: UIDatePicker, destination: UITextField){
    let dateFormatter = DateFormatter()
    dateFormatter.dateStyle = DateFormatter.Style.medium
    dateFormatter.timeStyle = DateFormatter.Style.none

    destination.text = dateFormatter.string(from: caller.date)  <-- I expected I could update the text here, as I'm referencing it through the parameter, but it doesn't work. However, no error is raised.
}


func createToolbar(sender: UITextField){
    let datePickerToolbar = UIToolbar()
    datePickerToolbar.sizeToFit()

    let doneButton = UIBarButtonItem(title: "Done", style: .plain, target: self, action: #selector(employeeRegisterController.dismissKeyboard))
    doneButton.tag = sender.tag

    datePickerToolbar.setItems([doneButton], animated: false)
    datePickerToolbar.isUserInteractionEnabled = true

    sender.inputAccessoryView = datePickerToolbar
}

@objc func dismissKeyboard(on: UIButton){
    view.endEditing(true)
}