Swift3: Live Uilabel Update on User Input

Swift3: Live UiLabel update on user input

Use the delegate method:

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    label.text = textField.text
    return true
}

Why my label left 1 character when updating UILabel from UITextField?

textField:shouldChangeCharactersIn:range:replacementString is called before the change is applied to the text field, this allows your app to veto the request and filter out unwanted content.

The problem is, you're relying on the text field's text. Instead, you need build the resulting value from the information passed to the delegate and apply that

Maybe something more like...

extension CreateEventVC: UITextFieldDelegate {
    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        let text = textField.text ?? ""
        eventNameLabel.text = (text as NSString).replacingCharacters(in: range, with: string)
        return true;
    }
}

Assign action to UITextField and update UILabel

Assumptions:

• Your text field is named textField
• Your label is named label

You can check it in that button action function like following:

    if let text = textField.text {
        if text == "Specified Text" {
            label.text = "Correct"
        }
    }

So if textField's text is equal to your specified text label's text will be "Correct", otherwise nothing will happen.

If by virtual send button you mean the return button of keyboard, you need to do the following in textFieldShouldReturn delegate method:

func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    if let text = textField.text {
        if text == "Specified text" {
            label.text = "Correct"
        }
        textField.text = ""
    }
    textField.resignFirstResponder() // this is optional, you might wanna hide keyboard or not
    return true
}

Update label.text at runtime

If you want to know when changes are done in the textFields, func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell is not the place you want to put your calculation code.

Instead you should listen to the event .editingChanged on text fields from your CellCustomized class.

class RiskPlan: UIViewController, UITableViewDelegate, UITableViewDataSource {

  @IBOutlet weak var tableView: UITableView!

  func numberOfSections(in tableView: UITableView) -> Int {
    return 1
  }

  func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return 1
  }

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

    return cell
  }
}

---

class CellCustomized: UITableViewCell {

  @IBOutlet weak var probability: UITextField!
  @IBOutlet weak var impact: UITextField!
  @IBOutlet weak var riskFactor: UILabel!

  var probability1 = 0
  var impact1 = 0

  override func awakeFromNib() {
    super.awakeFromNib()

    probability.addTarget(self, action: #selector(textOnTextFieldDidChange(textField:)), for: .editingChanged)
    impact.addTarget(self, action: #selector(textOnTextFieldDidChange(textField:)), for: .editingChanged)
  }

  func textOnTextFieldDidChange(textField: UITextField) {
    if textField === probability {
      probability1 = Int(textField.text!) ?? 0
    } else if textField === impact {
      impact1 = Int(textField.text!) ?? 0
    }

    riskFactor.text = String(probability1 * impact1)
  }

}

How do you display text from a user input? Swift 3.0

You can do this either using storyboards or programmatically. Both options works as of Xcode 8 Swift 3

Storyboards

1. Drag in a UITextField, a UIButton and UILabel from the library, onto you view controller
2. Create an IBOutlet for the UITextField and the UILabel to your ViewController.swift file.
3. Then create an IBAction for the UIButton to the same ViewController.swift file.

4. Write this code in the action function for your button:

   myLabel.text = myTextField.text

Your whole code should look like this:

import UIKit

class ViewController: UIViewController {

@IBOutlet weak var myTextField: UITextField!

@IBOutlet weak var myLabel: UILabel!

@IBAction func myButtonPressed(_ sender: AnyObject) {

    myLabel.text = myTextField.text

}

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view, typically from a nib.

}
}

Or Programmatically:

import UIKit

class ViewController: UIViewController {

// First create your components

let myTextField: UITextField = {
    let textField = UITextField()
    textField.backgroundColor = .lightGray //Just so you can see it
    textField.translatesAutoresizingMaskIntoConstraints = false
    return textField
}()

let myLabel: UILabel = {
    let label = UILabel()
    label.text = "Label text" //You may want to set this to something else to start with
    label.textAlignment = .center
    label.translatesAutoresizingMaskIntoConstraints = false
    return label
}()

let myButton: UIButton = {
    let button = UIButton()
    button.setTitle("Press me", for: .normal)
    button.setTitleColor(UIColor.blue, for: .normal)
    button.translatesAutoresizingMaskIntoConstraints = false
    return button
}()

//Then add them as subViews in the viewDidLoad method and set some constraints. 

override func viewDidLoad() {
    super.viewDidLoad()

    view.addSubview(myTextField)
    myTextField.widthAnchor.constraint(equalToConstant: 250).isActive = true
    myTextField.heightAnchor.constraint(equalToConstant: 50).isActive = true
    NSLayoutConstraint(item: myTextField, attribute: .centerX, relatedBy: .equal, toItem: view, attribute: .centerX, multiplier: 1, constant: 0).isActive = true
    NSLayoutConstraint(item: myTextField, attribute: .centerY, relatedBy: .equal, toItem: view, attribute: .centerY, multiplier: 1, constant: -100).isActive = true

    view.addSubview(myLabel)
    myLabel.widthAnchor.constraint(equalToConstant: 250).isActive = true
    myLabel.heightAnchor.constraint(equalToConstant: 50).isActive = true
    NSLayoutConstraint(item: myLabel, attribute: .centerX, relatedBy: .equal, toItem: view, attribute: .centerX, multiplier: 1, constant: 0).isActive = true
    NSLayoutConstraint(item: myLabel, attribute: .centerY, relatedBy: .equal, toItem: view, attribute: .centerY, multiplier: 1, constant: 0).isActive = true

    view.addSubview(myButton)
    myButton.widthAnchor.constraint(equalToConstant: 250).isActive = true
    myButton.heightAnchor.constraint(equalToConstant: 50).isActive = true
    NSLayoutConstraint(item: myButton, attribute: .centerX, relatedBy: .equal, toItem: view, attribute: .centerX, multiplier: 1, constant: 0).isActive = true
    NSLayoutConstraint(item: myButton, attribute: .top, relatedBy: .equal, toItem: myTextField, attribute: .bottom, multiplier: 1, constant: 10).isActive = true

//This sets the function for when the button is pressed 
    myButton.addTarget(self, action: #selector(ViewController.myButtonPressed), for: .touchUpInside)
}

//Add code here to when the button is pressed
func myButtonPressed() {

    myLabel.text = myTextField.text

}

}

Is there a way to hide a UILabel when the user starts typing, and then make it re-appear if the user removes all input?

You Can do it using add a target to your textFiled with a selector like this

1. add this target to ur viewDidLoad method

yourTextFiled.addTarget(self, action: #selector(self.textFieldDidChange(_:)), for: UIControl.Event.editingChanged)

1. create selector method like this below your viewDidLoad Method and set if textfield.text.isEmpty than label is hidden like this

    @objc func textFieldDidChange(_ textField: UITextField) {
        if textField.text!.isEmpty {
            label.isHidden = false
        } else {
            label.isHidden = true
        }
    }

Hope you get your desire thing !

How can I make a clickable UILabel in Swift 3?

Problem is with your Label memory allocation. You have created IBOutlet of label but not connected it with Interface from your Storyboard/XIB view controller.

Go to your Interface Builder: (Storyboard/XIB) View Controller ▶ Select 'Connection Inspector' ▶ Connect label outlet 'back' with Label interface element

How to do a live UITextField count while typing (Swift)?

To use the function below you need to implement the UITextFieldDelegate protocol on the text field you want to count. This gets called every time the UITextFields text changes:

Your class declaration should look something like this

class ViewController: UIViewController, UITextFieldDelegate

You should have an @IBOutlet similar to this

@IBOutlet var txtValue: UITextField

Set the UITextField s delegate to self.

override func viewDidLoad() {
    super.viewDidLoad()
    txtValue.delegate = self                
}

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
    let newLength = count(textField.text.utf16) + count(string.utf16) - range.length

    mylabel.text =  String(newLength) // Set value of the label
    // myCounter = newLength // Optional: Save this value
    // return newLength <= 25 // Optional: Set limits on input. 
    return true
}

Note that this function is called on all UITextFields so if you have several UITextFields you will need to add a logic to know witch one is calling this function.

update text field ui in swift ios

Same issue that everyone is having when wanting to do UI updates in Swift: do not ever update the UI in any secondary thread. And that means anything with closures. Since Swift is using closures so much, that issue is being seen a lot more but it isn't new.

See Swift Update Label (with HTML content) takes 1min for the correct way of doing things.

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