How to increase width of textfield according to typed text?

Question

I need to increase a text field\'s width according to its content. When the user inputs text, then the textfield size should increase automatically. I have one close (X) but

Answer 1

A cheeky workaround to get width for a particular string would be

func getWidth(text: String) -> CGFloat {
    let txtField = UITextField(frame: .zero)
    txtField.text = text
    txtField.sizeToFit()
    return txtField.frame.size.width
}

And to get the width,

let width = getWidth(text: "Hello world")
txtField.frame.size.width = width
self.view.layoutIfNeeded() // if you use Auto layout

If you have a constraint linked to txtField's width then do

yourTxtFieldWidthConstraint.constant = width
self.view.layoutIfNeeded() // if you use Auto layout

Edit We are creating a UITextField with a frame of basically all zeros. When you call sizeToFit(), it will set the frame of UITextField in a way that it will show all of its content with literally no extra spaces around it. We only wanted its width, so I returned the width of the newly created UITextField. ARC will take care of removing it from memory for us.

Update

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

        if textField.text != nil {
            let text = textField.text! as NSString
            let finalString = text.replacingCharacters(in: range, with: string)
            textField.frame.size.width = getWidth(text: finalString)
        }

        return true
    }