Here is an example of custom UITextField
that takes only numerical text and discards all other.
NOTE: For iPhone it is easy to do this using Number type keyboard, but for iPad there is no keyboard with Numbers only
class NumberTextField: UITextField {
required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
registerForTextFieldNotifications()
}
override init(frame: CGRect) {
super.init(frame: frame)
}
override func awakeFromNib() {
super.awakeFromNib()
keyboardType = .numberPad//useful for iPhone only
}
private func registerForTextFieldNotifications() {
NotificationCenter.default.addObserver(self, selector: #selector(NumberTextField.textDidChange), name: NSNotification.Name(rawValue: "UITextFieldTextDidChangeNotification"), object: self)
}
deinit {
NotificationCenter.default.removeObserver(self)
}
func textDidChange() {
text = filteredText()
}
private func filteredText() -> String {
let inverseSet = CharacterSet(charactersIn:"0123456789").inverted
let components = text!.components(separatedBy: inverseSet)
return components.joined(separator: "")
}
}
So, wherever we want text field which would take only numbers as input text, then we can use this custom UITextField