How to exclude special characters from android keypad for EditText

Question

Hi I want to show only numbers and characters on the keypad for EditText in android, I did try to add the attribute android:inputType = text|number but it did not work.

Please help me with any other better suggestion. thanks in advance.

score 37 · Answer 1 · edited Dec 10 '21 at 09:39

37

Use the filter for that. Here I am adding the code for filter.

  EditText etName = (EditText)findViewById(R.id.etName);
  InputFilter filter = new InputFilter() { 
        @Override
        public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) { 
            for (int i = start; i < end; i++) { 
                if (!Character.isLetterOrDigit(source.charAt(i))) { 
                    return ""; 
                } 
            } 
            return null; 
        }
  };
  etName.setFilters(new InputFilter[]{filter});

edited Dec 10 '21 at 09:39

pz64_

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answered Sep 07 '11 at 14:26

Aju

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1

you implement it same as I posted – Aju Sep 07 '11 at 14:47
2

Excellent this is just what I needed. Should work across most if not all character sets. – HGPB Sep 24 '12 at 00:21
1

There is problem with Pi, this allows Pi from source ... Need to add one condition for that as well. – MobileEvangelist Mar 21 '18 at 06:10

score 26 · Accepted Answer · answered Sep 07 '11 at 14:27

26

try to add the digits parameter to your editText:

android:digits="abcde.....012345789"

answered Sep 07 '11 at 14:27

Dyonisos

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i need to add space also how to include that – learner Sep 08 '11 at 12:33
1

for space give one space in that like this android:digits="abcde " – mobilemagic Sep 05 '12 at 14:13
19

Surely this must be a nightmare for multilingual apps? – HGPB Sep 24 '12 at 00:10
This will also block using emojis. – Ezequiel Adrian Sep 06 '21 at 13:08

score 6 · Answer 3 · edited Dec 10 '21 at 09:51

The solution with InputFilter provided here is not 100% correct as it will replace and throw out some valid characters from the input if they are right next to the invalid one.

For example we need to filter out all special characters and you enter text: olala[

The EditText field will pass the whole olala[ sentence to the filter and the return value will be "" meaning that we throw out valid olala as well.

Here is my solution:

InputFilter filter = (source, start, end, dest, dstart, dend)->{
    for (int i = start; i < end; i++) {
        char symbol = source.charAt(i);
        if (!isValidCharacter(symbol)) {
            StringBuilder buf = new StringBuilder();
            for(int j = start; j < end; j++)
            {
                symbol = source.charAt(j);
                if(isValidCharacter(symbol)) buf.append(symbol);
            }
            return buf.toString();
        }
    }
    return null;
};

We need double loop here to avoid memory allocation of StringBuilder for every method call with valid characters.

This answer is the most suitable one, because it excludes the unwanted characters. The accepted answer, instead, just limits to allowing valid characters. — Ezequiel Adrian, Sep 06 '21 at 13:27
Only solution that worked on all scenarios. Thanks for solution. — pz64_, Dec 10 '21 at 09:52

score 5 · Answer 4 · answered Jun 16 '17 at 10:48

5

If you want to add spaces you can give space after the last digit.

 android:digits="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890 "

answered Jun 16 '17 at 10:48

Thirupathi Yadav

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1

Not working with TextInputEdit – blackjack May 06 '22 at 14:38

Deepak · Answer 5 · 2020-02-17T10:18:47.983

try using this method it worked for me:

public static InputFilter[] getFilter(String blockChars) {
   return new InputFilter[]{(source, start, end, dest, dstart, dend) -> {
        for (int i = start; i < end; i++) {
            if (source != null && blockChars.contains("" + source.charAt(i))) {
                return source.subSequence(start, i);
            }
        }
        return null;
    }};

add this line for your edit text

edittext.setFilters(getFilter("@~"));

score 1 · Answer 6 · answered Mar 21 '18 at 06:35

The expected solution is to restrict user from entering special characters from keyboard.

The below solution uses RegX but adds it to strings.xml file so that will be taken care at the time of creating multilingual xmls.

Strings.xml

<string name="alpha_numeric_regx">[a-zA-Z 0-9]+</string>

Source file

 //Extracting forehand to avoid multiple calls to getString from Filter
        String alphaNumericRegX = getString(R.string.alpha_numeric_regx);
        mEditTextOtp.setFilters(new InputFilter[]{(source, start, end, dest, dStart, dEnd) -> {
            for (int i = 0; i < source.length(); i++) {
                if (source.equals("")) {
                    return source;
                }
                if (source.toString().matches(alphaNumericRegX)) {
                    return source;
                }
                return "";
            }
            return null;
        }});

Hope this will solve the prob. for new guys. :)

why do we need a for loop here, as you directly work on source strings — sunil, Dec 21 '18 at 13:55

score 1 · Answer 7 · answered Sep 08 '20 at 10:51

1

Kotlin

et_search.keyListener = DigitsKeyListener.getInstance(getString(R.string.alphanumeric))

String.xml

<string name="alphanumeric">0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ</string>

answered Sep 08 '20 at 10:51

Vanya Rachel

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score 0 · Answer 8 · answered Aug 18 '16 at 10:28

  //大兄弟，这么做就可以了。 
  InputFilter filter = new InputFilter() {
        @Override
        public CharSequence filter(CharSequence source, int start, int end,
                                   Spanned dest, int dstart, int dend) {
            for (int i = start; i < end; i++) {
                if (isChineseChar(source.charAt(i))) {
                    return "";
                }
            }
            return null;
        }
    };
    etName.setFilters(new InputFilter[]{filter});

//一条简单的规则。
private static boolean isChineseChar(char c) {
    Character.UnicodeBlock ub = Character.UnicodeBlock.of(c);
    return ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS;
}

score 0 · Answer 9 · answered Aug 12 '17 at 04:56

Its Working Restrict Special Symbol in Edittext

    private EditText your_editText ;
    private String blockCharacters = "(~*#^|$%&!";

    private InputFilter filter = new InputFilter() {

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

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

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        your_editText = (EditText) findViewById(R.id.your_editText);
        your_editText .setFilters(new InputFilter[] { filter });
    }

}

fetchSerotonin · Answer 10 · 2022-11-23T18:30:59.717

0

I couldn't edit a previous answer, so I did a Kotlin version of it (including whitespace):

private val userNameFilter =
    InputFilter { source, start, end, dest, dStart, dEnd ->
        for (i in start until end) {
            if (!Character.isLetterOrDigit(source[i]) && !Character.isWhitespace(source[i])) {
                return@InputFilter ""
            }
        }
        null
    }

edited Nov 23 '22 at 18:30

answered Nov 23 '22 at 18:08

fetchSerotonin

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How to exclude special characters from android keypad for EditText

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