How to restrict special characters from an Android

Question

How to restrict special characters from an Android EditText field?

Answer 1

I have solved this problem in my answer: Prevent special symbols in EditText. You can change the regex as per your requirement.

Answer 2

Just pass the EditText object to this method. Also add the values that is to be blocked in the variable blockCharacterSet.

private void disableSpecialChar(EditText editText) {
      final String blockCharacterSet = "<>";

      InputFilter filter = new InputFilter() {

       @Override
       public CharSequence filter(CharSequence source, int start, int end,
         Spanned dest, int dstart, int dend) {

        if (source != null && blockCharacterSet.contains(("" + source))) {
         return "";
        }
        return null;
       }
      };

      editText.setFilters(new InputFilter[] { filter });

     }

Answer 3

Have you tried adding the android:digits="abcde.....0123456789" attribute? Although the android:digits specify that it is a numeric field, it does work for me to set it to accept letters as well, and special characters as well (tested on SDK-7).

If this doesn't work then you'll have to implement KeyListener see: http://developer.android.com/reference/android/widget/TextView.html#setKeyListener(android.text.method.KeyListener)