Nic*_*k89 6 uibutton uitextfield ios is-empty swift
所以我的概念很简单,我有一个文本字段和一个标有"下一步"的按钮.如果用户没有在文本字段中放置任何内容,我希望将"下一步"按钮禁用给用户.为此,我运行了以下代码:
@IBAction func nextButton(sender: UIButton) {
if textField.text.isEmpty {
buttonLabel.userInteractionEnabled = false
}
}
这会根据需要禁用按钮,但问题是,如果文本然后在文本字段中输入,则按钮仍处于禁用状态.我已经尝试在"if"语句之后添加"else"语句来反转我所说的是否有效,但事实并非如此.
任何帮助非常感谢.
缺口
我的代码:
import UIKit
class ViewController: UIViewController, UITextFieldDelegate, UIPickerViewDataSource, UIPickerViewDelegate {
func imageEffect() {
// Set vertical effect for background
var verticalMotionEffect : UIInterpolatingMotionEffect =
UIInterpolatingMotionEffect(keyPath: "center.y",
type: .TiltAlongVerticalAxis)
verticalMotionEffect.minimumRelativeValue = -20
verticalMotionEffect.maximumRelativeValue = 20
// Set horizontal effect for background
var horizontalMotionEffect : UIInterpolatingMotionEffect =
UIInterpolatingMotionEffect(keyPath: "center.x",
type: .TiltAlongHorizontalAxis)
horizontalMotionEffect.minimumRelativeValue = -20
horizontalMotionEffect.maximumRelativeValue = 20
// Create group for background to combine both
var group : UIMotionEffectGroup = UIMotionEffectGroup()
group.motionEffects = [horizontalMotionEffect, verticalMotionEffect]
// Add both effects to your view for background
myBackgroundView.addMotionEffect(group)
}
var datePickerView:UIDatePicker = UIDatePicker()
@IBAction func textFieldEdited(sender: UITextField) {
var datePickerView : UIDatePicker = UIDatePicker()
datePickerView.datePickerMode = UIDatePickerMode.Date
sender.inputView = datePickerView
datePickerView.addTarget(self, action: Selector("handleDatePicker:"), forControlEvents: UIControlEvents.ValueChanged)
}
func handleDatePicker(sender: UIDatePicker) {
var dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "dd MMMM yyyy"
questionTextField.text = dateFormatter.stringFromDate(sender.date)
}
var countryData = ["United Kingdom", "France", "Spain", "Germany", "Berlin", "Eygpt", "United States"]
var pickerView:UIPickerView = UIPickerView()
@IBOutlet var progressStatus: UIProgressView!
@IBOutlet var barImage: UIImageView!
@IBOutlet var questionLabel: UILabel!
@IBOutlet var buttonBarImage: UIImageView!
@IBOutlet var buttonLabel: UIButton!
@IBOutlet var myBackgroundView: UIImageView!
@IBOutlet var questionTextField: UITextField!
let questions = ["Where are you going?", "What are you doing there?", "When do you go?"]
var currentQuestionIndex = 0
let placeholder = ["Country", "Activity", "Date"]
var currentPlaceholderIndex = 0
@IBAction func nextButton(sender: AnyObject) {
if currentQuestionIndex == 0 {
progressStatus.setProgress(0.333, animated: true)
} else if currentQuestionIndex == 1 {
progressStatus.setProgress(0.666, animated: true)
} else {
progressStatus.setProgress(1, animated: true)
}
// Initial setup on button press
questionTextField.hidden = false
barImage.hidden = false
questionTextField.placeholder = placeholder[currentPlaceholderIndex]
questionLabel.text = questions[currentQuestionIndex]
questionTextField.resignFirstResponder()
// Reset text field to have no text
questionTextField.text = ""
// Displays the questions in array and displays the placeholder text in the textfield
if currentQuestionIndex <= questions.count && currentPlaceholderIndex <= placeholder.count {
currentQuestionIndex++
currentPlaceholderIndex++
//progressStatus.setProgress(0.333, animated: true)
buttonLabel.setTitle("Next", forState: UIControlState.Normal)
// Animate text for questionLabel
UIView.animateWithDuration(1.0, delay: 0.0, usingSpringWithDamping: 0.9, initialSpringVelocity: 0.5, options: nil, animations: {
self.questionLabel.center = CGPoint(x: -110 , y: 305 + 20)
}, completion: nil)
} else {
//Add some logic here to run whenever the user has answered all the questions.
}
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
questionTextField.delegate = self
pickerView.delegate = self
pickerView.dataSource = self
// Applies the image effect to the image in myBackgroundImage
imageEffect()
// Sets the button text
buttonLabel.setTitle("Get started", forState: UIControlState.Normal)
// Sets the question text to be blank
questionLabel.text = ""
// Sets placeholder text in the text field
questionTextField.placeholder = ""
// Hides the text field
questionTextField.hidden = true
// Hides the image background for the text field
barImage.hidden = true
// Sets the progress bar to nil
progressStatus.setProgress(0, animated: true)
if questionTextField.text.isEmpty {
buttonLabel.userInteractionEnabled = false
}
}
func textFieldDidBeginEditing(textField: UITextField) {
buttonLabel.userInteractionEnabled = true
switch currentQuestionIndex {
case 0:
// TODO: Add UIPickerView
self.view.addSubview(datePickerView)
case 2:
// TODO: Add UIDatePicker
self.view.addSubview(datePickerView)
default:
println("default")
}
}
// resigns the keyboard when user presses the return/next key on keyboard
func textFieldShouldReturn(textField: UITextField) -> Bool {
questionTextField.resignFirstResponder()
return true
}
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return countryData.count
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
return countryData[row]
}
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
questionTextField.text = countryData[row]
pickerView.hidden = true
}
// Resigns the keyboard if the user presses anywhere on the screen
override func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
self.view.endEditing(true)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
编辑：
设置myButton.userInteractionEnabled = false在viewDidLoad或 中viewWillAppear。
设置你textField的delegate。
进而
func textFieldDidBeginEditing(textField: UITextField) {
if !textField.text.isEmpty
myButton.enable = true
} else {
buttonLabel.enable = false
}
}