Question

The question is about android Spinners working when “Gone” and then “Visible” again.

I’ve got a form where spinner is hidden (“Gone”) by default. If user checks checkbox, it appears and allows to choose something. The problem is when I do submit info from the form without touching the checkbox (i.e. default value is chosen from spinner), App crashes with nullpointer exception – despite I`m setting spinner as visible.

If I click checkbox (even twice, to make Spinner gone again) – everything works fine. If I use invisible instead of gone, everything works fine even without touching the button.

How to make it work with spinner “Gone” by default?

Here`s code on how checkbox behaves (onclick checkbox):

        case R.id.checkboxUseDefaultURLList:
        {
            final CheckBox checkBoxDefaultList = (CheckBox) findViewById(R.id.checkboxUseDefaultURLList);
            final TextView textViewEmpty = (TextView) findViewById(R.id.textBlank);
            final Spinner s2 = (Spinner) findViewById(R.id.spinnerURLList);
            if (checkBoxDefaultList.isChecked()) {
                textViewEmpty.setVisibility(View.GONE); // GONE
                textViewEmpty.invalidate();
                s2.setVisibility(View.GONE); // GONE
                s2.invalidate();
                }           
            if (!checkBoxDefaultList.isChecked()) {
                textViewEmpty.setVisibility(View.VISIBLE); // VISIBLE
                textViewEmpty.invalidate();
                s2.setVisibility(View.VISIBLE); // VISIBLE
                s2.invalidate();
                }
            break;
        }

here`s how I get values from Spinner (in onclick of “submit” button):

                    Spinner spinURLList = (Spinner) findViewById(R.id.spinnerURLList);
                spinURLList.setVisibility(View.VISIBLE);
                spinURLList.invalidate();
                spinURLList.setSelection(0);
                TextView chosenURLTV = (TextView) spinURLList.getSelectedView();
                String urlListSelected = chosenURLTV.getText().toString();

Any ideas why it crashes if I don`t click on checkbox before submitting?

Answer 1

It may be a problem of assigning the TextView the text in the spinner. Try:

String urlListSelected = spinURLList.getSelectedItem().toString();