EditText to allow unique letters

Question

how to make edittext should get unique letters as input.

if already letter is there in the edittext we should filter it

Thanks in advance.

Answer 1

You can check inserted text after each input character.

by implementing TextWatcher

see this answer

you can write your code in

@Override
public void afterTextChanged(Editable s) {
     // your code for checking unique character here

}

Answer 2

My idea is you register a TextWatcher to your EditText and override afterTextChanged.

And store it using Shared Preferences.

Answer 3

try using TextWatcher to filter chars input by user

   TextWatcher mTextWatcher = new TextWatcher() {
        private CharSequence temp;

        @Override
        public void beforeTextChanged(CharSequence s, int arg1, int arg2,
                int arg3) {
            temp = s;
        }

        @Override
        public void onTextChanged(CharSequence s, int arg1, int arg2,
                int arg3) {

        }

        @Override
        public void afterTextChanged(Editable s) {

                   //CHECK HERE FOR UNIQUE LETTERS as INPUT BY USER and REMOVE IT
            }
        }
    };