How to toast when letter is inputed in EditText

Question

I am a beginner starting to design a simple app to keep track of golf scores. I spent some time trying to figure out how to provide the user with a notification that they are unable to enter a letter under the score text box. I have tried using an array that contains the entire alphabet but have not been able to get it to work. I am currently now experimenting with InputFilter but I am not having any success; the app simply crashes when a letter has been entered.

    EditText input1 = (EditText)findViewById(R.id.scorePrompt);
    TextView output1 = (TextView)findViewById(R.id.textTotal);
    String blankCheck = input1.getText().toString(); //CHANGE INPUT IN scorePrompt TO STRING

    InputFilter filter = new InputFilter() {
        public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {
            for (int i = start; i < end; i++) {
                if (Character.isLetter(source.charAt(i))) { // Accept only letter & digits ; otherwise just return
                    Toast.makeText(getApplicationContext(),"NO LETTERS",Toast.LENGTH_SHORT).show();
                    return "";
                }
            }
            return null;
        }
    };

I suspect that it is because I am not directly connecting the Inputfilter to my blankCheck, but I am unsure. Any help is appreciated!

see https://stackoverflow.com/questions/8543449/how-to-use-the-textwatcher-class-in-android — TWL, Jul 31 '17 at 03:18
Possible duplicate of [Unfortunately MyApp has stopped. How can I solve this?](https://stackoverflow.com/questions/23353173/unfortunately-myapp-has-stopped-how-can-i-solve-this) — Code-Apprentice, Jul 31 '17 at 05:03
See the above question for suggestions about how to figure out the cause of the error. — Code-Apprentice, Jul 31 '17 at 05:03

score 0 · Answer 1 · answered Jul 31 '17 at 03:32

0

Often the answer you're looking for is a result of a problem that originates elsewhere.

If you'd like your users to input numbers rather than text, the best solution would be to specify an input type of "number" on the EditText field they are typing in. This will limit the keyboard input to only allow numbers.

<EditText
    android:inputType="number"
    .... other attributes
</EditText>

answered Jul 31 '17 at 03:32

themichaelscott

496
4
10

Thank you for the reply! I am sort of confused as to how I am supposed to implement this into my code. My plan is to eventually add more features on this activity which will require text input as well so I therefore don't want to completely prevent letter input. I currently have an `if` statement to check for a blank input in my EditText, and an `else` for all other cases. Would I be able to add your chunk of code into this `else` method? – Raymond Nguyen Aug 02 '17 at 05:19
No, @RaymondNguyen, my suggestion will change the keyboard from an alpha/numeric keyboard to a 10-key and won't allow alpha characters. It sounds like my suggestion doesn't align with what you're after. – themichaelscott Jan 20 '18 at 08:19

score 0 · Answer 2 · answered Jul 31 '17 at 05:01

U can make use of Regex for this, please see the below code :

// Define a pattern you want to use as below. // I'm only supporting the below :

Pattern keyPattern = Pattern.compile("[0-9a-zA-Z,._]+");

yourEditText.addTextChangedListener(new TextWatcher() {
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {}

    @Override
    public void afterTextChanged(Editable s) {
    if (!keyPattern .matcher(yourEditText.getText()).matches()) {
        Toast.makeText(getApplicationContext(),"Your Message",Toast.LENGTH_SHORT).show();
                    return "";
 }
});

Hope this helps!!!

How to toast when letter is inputed in EditText

2 Answers2