iOS 15.5, Xcode 13.31, Swift 5, UIKit 환경에서 진행했습니다. func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool { let allowedCharacters = CharacterSet(charactersIn: "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuxyz").inverted let components = string.components(separatedBy: allowedCharacters) let filtered = components.join..
