Why Scrolling Up and Down In GridView Changes Registries in SharedPreferences?

Question

My question is similar to this and this. But I cannot apply the solutions in those questions to my case.

My case is as follows: I have GridView consists of just CheckBoxes. I set setOnCheckedChangeListener in my Adapter's getView method, so that as soon as the status of CheckBox is changed, current status of the CheckBox is registered to SharedPreferences. And in getView also, I'm reading the current status of the CheckBox and set its status as so. Yet scrolling down and back up makes the checked boxes unchecked.

How can I solve this problem? Here is my custom adapter:

public class KnowledgeItemAdapter extends ArrayAdapter<KnowledgeItem> {
    private String currentKey;
    public KnowledgeItemAdapter(Activity context, ArrayList<KnowledgeItem> knowledgeItems){
        super(context, 0, knowledgeItems);
    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
        View knowledgeItemView = convertView;
        if (knowledgeItemView == null){
            knowledgeItemView = LayoutInflater.from(getContext()).inflate(R.layout.item_knowledge, parent, false);
        }

        knowledgeItemView.setClickable(true);
        knowledgeItemView.setFocusable(true);
        knowledgeItemView.setBackgroundResource(android.R.drawable.menuitem_background);

        final KnowledgeItem currentKnowledgeItem = getItem(position);
        final CheckBox knowledgeCheckBox = (CheckBox) knowledgeItemView.findViewById(R.id.item_knowledge_check_box);
        final SharedPreferences prefs = getContext().getSharedPreferences("com.example.myapplication", Context.MODE_PRIVATE);
        currentKey = currentKnowledgeItem.getPrefsKey();
        Boolean status = prefs.getBoolean(currentKey, false);

        knowledgeCheckBox.setText(currentKnowledgeItem.getText());
        knowledgeCheckBox.setChecked(status);
        knowledgeCheckBox.setOnCheckedChangeListener( //this);
                new CompoundButton.OnCheckedChangeListener() {
                    @Override
                    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                        prefs.edit().putBoolean(currentKnowledgeItem.getPrefsKey(), isChecked).apply();
                    }
                }
        );

        return knowledgeItemView;
    }

}

Have you tried using onClickListener instead as suggested in answer number 2 of :https://stackoverflow.com/questions/17234399/in-gridview-checkbox-is-unchecked-while-scrolling-gridview-up-and-down — Omkar C., Dec 21 '19 at 00:22
I had tried it. It didn't work until I change this and that. I'm posting the answer now. — Saba, Dec 21 '19 at 09:09

score 1 · Accepted Answer · answered Dec 21 '19 at 09:15

OK I've figured out the answer finally. I've changed the onCheckedChangeListener with onClickListener.

    knowledgeItemView.setOnClickListener(
            new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    Log.e("On Click Listener", currentKey);
                    if(knowledgeCheckBox.isChecked()){
                        knowledgeCheckBox.setChecked(false);
                        prefs.edit().putBoolean(currentKey, false).apply();
                    } else {
                        knowledgeCheckBox.setChecked(true);
                        prefs.edit().putBoolean(currentKey, true).apply();
                    }
                }
            }
    );

And do not forget to change the clickable xml attribution of the checkbox to false. Otherwise click events of checkbox and view conflict.

Why Scrolling Up and Down In GridView Changes Registries in SharedPreferences?

1 Answers1