How to use the TextWatcher class in Android?

Question

Can anyone tell me how to mask the substring in EditText or how to change EditText substring input to password type or replace by another character like this 123xxxxxxxxx3455

 String contents = et1.getText().toString();
 et1.setText(contents.replace.substring(0, contents.length()-2),"*");

Please, tell me how I can use the TextWatcher method in Android.

Answer 1

For use of the TextWatcher...

et1.addTextChangedListener(new TextWatcher() {
    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {

        // TODO Auto-generated method stub
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {

        // TODO Auto-generated method stub
    }

    @Override
    public void afterTextChanged(Editable s) {

        // TODO Auto-generated method stub
    }
});