How to UpperCase all the letters of a textField?

Question

I have a textField and I want to only accept UpperCase letters on it, so if I type 'asd' it have to be converted to 'ASD' in the field.

I already tried TextCapitalization.character but it keeps the caps lock activated and If I turn it off my next letters are showed in lower case. I don't want to accept lower case letters in any situation.

Is there a way to do it?

Edit - What I did

TextField(
      
        textCapitalization: TextCapitalization.characters,
    )

Does this answer your question? [How to validate flutter text field for Email or Phone or Null?](https://stackoverflow.com/questions/66307037/how-to-validate-flutter-text-field-for-email-or-phone-or-null) — vincenzopalazzo, Nov 18 '21 at 19:05
No. I want to UpperCase all the letters inputed in the textfield — HelloWorldd, Nov 18 '21 at 19:07
Does this answer your question? [Flutter TextField value always uppercase & debounce](https://stackoverflow.com/questions/49238908/flutter-textfield-value-always-uppercase-debounce) — Midhun MP, Nov 18 '21 at 19:24

Eugene Kuzmenko · Accepted Answer · 2021-11-18T19:28:03.833

1

You can use custom TextInputFormatter inside TextField( inputFormatters: [UppercaseInputFormatter()], ...)

class UppercaseInputFormatter extends TextInputFormatter {
  @override
  TextEditingValue formatEditUpdate(TextEditingValue oldValue, TextEditingValue newValue) {
    return newValue.copyWith(text: newValue.text.toUpperCase());
  }

}

edited Nov 18 '21 at 19:28

answered Nov 18 '21 at 19:23

Eugene Kuzmenko

1,216
10
12

And how can I use it in the textfield? – HelloWorldd Nov 18 '21 at 19:25
@HelloWorldd I updated my answer. – Eugene Kuzmenko Nov 18 '21 at 19:26

How to UpperCase all the letters of a textField?

1 Answers1