How to change label color when you change label text

Question

Im new in this... I have one text field and one label... I would like to change label color in case when message in text field and label text are not equal. This is my start:

@IBAction func tapMeButton(_ sender: Any) {

    label.text = txtField.text

    }

How can I do this?

`UILabel`s have a `textColor` field, which takes a `UIColor`. You can use an `if` statement to determine if the messages are the same (you might want to set both strings to lowercase, if you don't care about capitalisation). — Rich Tolley, Jan 26 '18 at 10:09

Shehata Gamal · Answer 1 · 2018-01-26T10:15:07.350

2

Add this line to viewDidLoad

  textField.addTarget(self, action: #selector(textFieldDidChange(_:)), for: .editingChanged)

and

@objc func textFieldDidChange(_ textField: UITextField) {

   if(label.text != txtField.text)
  {
      label.textColor = UIColor.red
  }

}

@IBAction func tapMeButton(_ sender: Any) {

    label.text = txtField.text
}

edited Jan 26 '18 at 10:15

answered Jan 26 '18 at 10:06

Shehata Gamal

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Thanks for answer. But I want to change color when I change text. In the begining my text field and my label are same when I press the button. And then, when I want to change label color when I write new text in text field. – Sonya Kovach Jan 26 '18 at 10:11

score 1 · Accepted Answer · answered Jan 26 '18 at 10:25

UITextField provide delegate method, you can use this code to check both Value are same or not.

    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        let nsString = textField.text as NSString?
        let newString = nsString?.replacingCharacters(in: range, with: string)

        if(self.lbl.text != newString) {
             self.lbl.textColor = UIColor.red
        }
        else {
             self.lbl.textColor = UIColor.green
        }

        return true;
     }

score 0 · Answer 3 · answered Jan 26 '18 at 10:17

First add target for getting the change of text.

textField.addTarget(self, action: #selector(textFieldDidChange(_:)), for: .editingChanged)

func textFieldDidChange(_ textField: UITextField) {
    if(label.text != textField.text)
 {
   label.textColor = UIColor.red
 }
}

You can also see this: https://stackoverflow.com/a/28395000/5167909

score 0 · Answer 4 · edited Jan 26 '18 at 12:48

To do this you have to understand the the textfield more,

Every textfield comes with delegate method to do various functionalities around it. so first in your viewDidLoad method, add delegate to it like this
```
yourTextField.delegate = self
```

Add the delegate methods by assigning textFieldDelegate to your class by adding its extension. It will provide you text at real time, while user starts typing and before even get added to textField

extension YourViewController:UITextFieldDelegate {


    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {


    if let text = textField.text as NSString? {
        let txtAfterUpdate = text.replacingCharacters(in: range, with: string)

        if txtAfterUpdate == label.text {

            label.backgroundColor = UIColor.red

        } else {

            label.backgroundColor = UIColor.black
            }


        }
        return true

    }



}

How to change label color when you change label text

4 Answers4