Uppercase characters in UItextfield

Question

I have a question about iOS UIKeyboard.

I have a UITextField and I would to have the keyboard with only uppercase characters.<

Answer 1

For those looking for a Swift version.

Swift 4

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

    return false
}

Original answer

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool {
    textField.text = (textField.text as NSString).stringByReplacingCharactersInRange(range, withString: string.uppercaseString)

    return false
}

Using the Capitalization: All Characters property just forces keyboard to open with caps lock on, but lets the user to turned it off.