Swift UITextfield 委托 Function “shouldChangeCharactersIn” - 如何停止编辑 UITextfield？

Question

I have a problem, I have two Textfields and want a max length of 20 Characters for both.

I use the following code but it only works for my first Textfield. What did I wrong? I hope someone can help me.

func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        
        if textField === nameTextField {
            
            let currentText = nameTextField.text
            guard let stringRange = Range(range, in: currentText!) else {
                return false
            }
            
            let updateText = currentText?.replacingCharacters(in: stringRange, with: string)
            return updateText?.count ?? 0 < 20
            
        } else if textField === numberTextField {
            let currentText = numberTextField.text
            guard let stringRange = Range(range, in: currentText!) else {
                return false
            }
            
            let updateText = currentText?.replacingCharacters(in: stringRange, with: string)
            return updateText?.count ?? 0 < 20
            
        }
        return true
    }

Answer 1

You probably forgot to set the delegate for the second one.

Also no need for this complex logic: Just keep the first 20 like:

textView.text = String(textView.text.prefix(20))