Cannot get right data from ListView ArrayList

Question

I'm using ListView's ArrayList and add items by adapter. But after " convertView == null " code, I cannot get right data from the arrayList.

For example, I push datas < position 0 - "data0" > , < position 1 - "data1" > in the arrayList, but arrayList[1] return "data0", not "data1".

In other parts, I can get right data from ArrayList, but it failed only after " convertView == null " code.

Here's my adapter code

public class KeikoItemAdapter extends BaseAdapter {
    private static final int ITEM_VIEW_TYPE_MAIN = 0;
    private static final int ITEM_VIEW_TYPE_YM = 1;

    final ArrayList<Keiko_item_Data> items;

    public KeikoItemAdapter (ArrayList <Keiko_item_Data> itemList){
        if ( itemList == null) {
            items = new ArrayList<Keiko_item_Data>();
        } else {
            items = itemList;
        }
    }

    public void addMainItem(String month, String date, String day, String diaryLog, String year) {
        Keiko_item_Data item = new Keiko_item_Data(month, date, day, diaryLog, year);
        item.setType(ITEM_VIEW_TYPE_MAIN);
        items.add(item);

    }

    public void addYmItem (String year, String month) {
        Keiko_item_Data item = new Keiko_item_Data(year, month);
        item.setType(ITEM_VIEW_TYPE_YM);
        items.add(item);
    }


    @Override
    public int getViewTypeCount() {
        return 2;
    }

    @Override
    public int getItemViewType(int position) {
        return items.get(position).getType();
    }

    @Override
    public int getCount() {
        return items.size();
    }

    @Override
    public Object getItem(int position) {
        return items.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        final Context context = parent.getContext();
        int viewType = getItemViewType(position); 

        Keiko_item_Data listViewItem = items.get(position);



        if ( convertView == null ){
            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

            switch (viewType) {
                case ITEM_VIEW_TYPE_MAIN:
                    convertView = inflater.inflate(R.layout.keiko_item_design, parent, false);

                    Keiko_item_Data itemHolder = new Keiko_item_Data();

                    itemHolder.dayView = (TextView) convertView.findViewById(R.id.dayText);
                    itemHolder.dateView = (TextView) convertView.findViewById(R.id.dateText);
                    itemHolder.diaryView = (TextView) convertView.findViewById(R.id.diaryEdit);

                    convertView.setTag(itemHolder);

                    break;

                case ITEM_VIEW_TYPE_YM:
                    convertView = inflater.inflate(R.layout.keiko_month_item_design, parent, false);

                    Keiko_item_Data ymItemHolder = new Keiko_item_Data();

                    ymItemHolder.monthView = (TextView) convertView.findViewById(R.id.monthText);
                    ymItemHolder.yearView = (TextView) convertView.findViewById(R.id.yearText);

                    convertView.setTag(ymItemHolder);

            }

            final Keiko_item_Data finalHolder;


            switch (viewType) {
                case ITEM_VIEW_TYPE_MAIN:
                    finalHolder = (Keiko_item_Data) convertView.getTag();
                    finalHolder.dateView.setText(String.valueOf(listViewItem.getDate()));
                    finalHolder.dayView.setText(String.valueOf(listViewItem.getDay()));
                    finalHolder.diaryView.setText(listViewItem.getDiaryLog());
                   break;

                case ITEM_VIEW_TYPE_YM:
                    finalHolder = (Keiko_item_Data) convertView.getTag();
                    finalHolder.yearView.setText(String.valueOf(listViewItem.getYearData()));
                    finalHolder.monthView.setText(String.valueOf(listViewItem.getMonthData()));
                    break;

            }


            }

        return convertView;
    }
}

if datas are in one row, I put out some and use them at ( ITEM_VIEW_TYPE_YM ) and use others at ( ITEM_VIEW_TYPE_MAIN ) . — yjyjy131, Feb 22 '20 at 13:04
Thank you for trying to solve this problem . I got answer from this page . [link](https://stackoverflow.com/questions/6953866/convertview-is-being-passed-as-null-even-if-the-view-exists) — yjyjy131, Feb 22 '20 at 13:36

score 0 · Answer 1 · answered Feb 21 '20 at 17:04

The position of the adapter is relative to the view and not the object of the listview, meaning it will include ITEM_VIEW_TYPE_MAIN views & ITEM_VIEW_TYPE_YM views you need to subtract the position depending on how you build your listviews in order to get the right item of your listview

Cannot get right data from ListView ArrayList

1 Answers1