Maybe it's a bit late for an answer here, but as I have a working solution someone might find it useful.
Well, in the following textfield delegate method, check if the new string contains any lowercase characters. If so, then:
- Append the character that was just typed to the textfield's text.
- Make all the textfield's text uppercased.
- Make sure that
false
is returned by the method.
Otherwise just return true
and let the method work as expected.
Here's its implementation:
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
var returnValue = true
let lowercaseRange = string.rangeOfCharacter(from: CharacterSet.lowercaseLetters)
if let _ = lowercaseRange?.isEmpty {
returnValue = false
}
if !returnValue {
textField.text = (textField.text! + string).uppercased()
}
return returnValue
}
The above has worked perfectly for me, and a similar implementation works for textviews too, after making the proper adjustments first of course.
Hope it helps!