关于 swift:UIDatePicker，默认值为 nil – iOS

UIDatePicker with default nil value - iOS

我搜索了很多，但没有找到解决方案。谁能帮我找出如何将 UIDatePicker 初始值设置为空文本字段？？

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import UIKit
import Alamofire
import KVNProgress

class EditProfileVC: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate
{
@IBOutlet var datePickerView: UIView!
@IBOutlet var datePicker: UIDatePicker!

@IBOutlet var birthdayText: UnderLineTextField!
@IBOutlet var bioText: UnderLineTextField!

@IBOutlet var scrollView: UIScrollView!
var imagePicker = UIImagePickerController()

var photoFlag = -1

let activityView = UIActivityIndicatorView(activityIndicatorStyle: .whiteLarge)

var singleTonInstance = SingleTon.sharedDataContainer

var email =""
var token =""

override func viewDidLoad()
{
super.viewDidLoad()

self.birthdayText.text =""
if #available(iOS 11.0, *)
{
navigationController?.navigationBar.prefersLargeTitles = false
}
else
{
// Fallback on earlier versions
}

SwiftyPlistManager.shared.getValue(for:"access_token", fromPlistWithName:"AccountDetails") { (result, err) in

if err == nil
{
self.token = (result as? String)!
}
}

activityView.color = UIColor.blue
activityView.center = self.view.center

self.view.addSubview(activityView)

self.datePickerView.isHidden = true

self.genderTxt.isUserInteractionEnabled = false
self.birthdayText.isUserInteractionEnabled = false

imagePicker.delegate = self

datePicker.addTarget(self, action: #selector(datePickerChanged), for: .valueChanged)

self.getProfileDetails()

}

@objc func savePressed()
{
self.activityView.isHidden = false
self.activityView.startAnimating()

let dateFormatter = DateFormatter()
dateFormatter.dateFormat ="MMMM dd, YYYY"
let date = dateFormatter.date(from: self.birthdayText.text!)
dateFormatter.dateFormat ="dd-MM-yyyy"
let dob = dateFormatter.string(from: date!)

let appDelegate = UIApplication.shared.delegate as! AppDelegate

let urlString = appDelegate.serverUrl +"edit_profile?full_name=\\(self.fullNameText.text!)&dob=\\(dob)&gender=\\(self.genderTxt.text!)&bio_data=\\(self.bioText.text!)&location=\\(self.locationText.text!)&web_site=\\(self.webTextField.text!)&token=\\(self.token)"

}

@objc func datePickerChanged(sender: UIDatePicker)
{
let formatter = DateFormatter()
formatter.dateFormat ="MMMM dd, YYYY"
birthdayText.text = formatter.string(from: sender.date)
}
override func didReceiveMemoryWarning()
{
super.didReceiveMemoryWarning()
}
func getProfileDetails()
{
self.activityView.isHidden = false
self.activityView.startAnimating()

let appDelegate = UIApplication.shared.delegate as! AppDelegate

let urlString = appDelegate.serverUrl +"view_profile?token=\\(self.token)"

}
}
}

@IBAction func birthdayTapped(_ sender: Any)
{
self.datePickerView.isHidden = false
}
}

上面的代码是我的整个viewcontroller类代码任何人都可以请你帮我找出解决方案。我将birthdayText的值分配为nil I ViewController但没有用。

相关讨论

UITextField 的 text 属性默认为空。所以下面的代码按预期工作。将其与您的代码进行比较：

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class ViewController: UIViewController {

private let textField: UITextField = {
let tf = UITextField()
tf.borderStyle = .roundedRect
tf.placeholder ="Choose date and time"
tf.text ="" // not even necessary
return tf
}()

lazy private var datePicker: UIDatePicker = {
let dp = UIDatePicker()
dp.addTarget(self, action: #selector(datePickerValueChanged), for: .valueChanged)
return dp
}()

lazy private var dateFormatter: DateFormatter = {
let df = DateFormatter()
df.dateStyle = .short
df.timeStyle = .short
return df
}()

@objc private func datePickerValueChanged(datePicker: UIDatePicker) {
textField.text = dateFormatter.string(from: datePicker.date)
}

override func viewDidLoad() {
super.viewDidLoad()

let stackView = UIStackView(arrangedSubviews: [textField, datePicker])
stackView.axis = .vertical

view.addSubview(stackView)
stackView.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
stackView.topAnchor.constraintEqualToSystemSpacingBelow(view.safeAreaLayoutGuide.topAnchor, multiplier: 1),
stackView.leadingAnchor.constraintEqualToSystemSpacingAfter(view.safeAreaLayoutGuide.leadingAnchor, multiplier: 1),
view.safeAreaLayoutGuide.trailingAnchor.constraintEqualToSystemSpacingAfter(stackView.trailingAnchor, multiplier: 1)
])
}

}

结果：

result

更新：

您的问题似乎是您在 viewDidLoad 的末尾调用了 self.getProfileDetails()。在该方法中，您有设置文本的行 self.birthdayText.text = dateFormatter.string(from: date!)。