Question

当我选择应用停止响应的日期时。我想选择日期并在文本字段中显示它而不按完成按钮。所以我希望看到现场直播。

如何根据TextField上选定的日期选择器打印年龄？

import UIKit
import Firebase

class SignUpEmailSegue0: UIViewController {
    @IBOutlet weak var dateBirthday: UITextField!

    @IBAction func dateBirthdayEdit(_ sender: UITextField) {
        let datePickerView = UIDatePicker()
        datePickerView.datePickerMode = UIDatePickerMode.date

        sender.inputView = datePickerView
        datePickerView.addTarget(self, action: #selector(handleDatePicker), for: UIControlEvents.valueChanged)
    }

    @objc func handleDatePicker(sender: UIDatePicker) {
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "dd/MMM/yyyy"
        dateBirthday.text = dateFormatter.string(from: sender.date)
    }
}

Answer 1

尝试按以下方式更改代码 - 使用#selector()并将您的功能展示给@objc

datePickerView.addTarget(self, action: #selector(handleDatePicker), for: UIControlEvents.valueChanged)


@objc func handleDatePicker(sender: UIDatePicker) {
    let dateFormatter = DateFormatter()
    dateFormatter.dateFormat = "dd-MM-yyyy"
    dateBirthday.text = dateFormatter.string(from: sender.date)
}

回答关于如何获得年龄的第二个问题：

let gregorian = Calendar(identifier: .gregorian)
let ageComponents = gregorian.dateComponents([.year], from: sender.date, to: Date())
if let age = ageComponents.year {
    print(age)
}

如何根据文本字段上选定的日期选择器打印年龄？

1 个答案: