why getchild method in BaseExpandableListAdapter calling two times from each child?

Question

I am using BaseExpandableListAdapter for displaying data is expandable list view. I have a scenario where I have to pop and push childs in groups. But unfortunately getchild method is calling two times for each child so I can not remove them because it give index out of range exception. Am I missing any thing important?

import android.content.Context;
import android.graphics.Typeface;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.EditText;
import android.widget.TextView;

public class adpFolderWithTaskDone extends BaseExpandableListAdapter {

    private Context _context;
    private List<clsTaskDoneDates> _listDataHeader; // header titles
    SimpleDateFormat dateFormat1 = new SimpleDateFormat("EEE MMM dd");
    SimpleDateFormat dateFormat2 = new SimpleDateFormat("HH:mm");
    // child data in format of header title, child title
    private HashMap<clsTaskDoneDates, List<clsTasks>> _listDataChild;
    int i=0;
    int j=0;

    public ArrayList<View> ChildIds=new ArrayList<View>();


    Typeface tf ;

    public adpFolderWithTaskDone(Context context, List<clsTaskDoneDates> listDataHeader,
            HashMap<clsTaskDoneDates, List<clsTasks>> listChildData) {
        this._context = context;
        this._listDataHeader = listDataHeader;
        this._listDataChild = listChildData;

        tf = Typeface.createFromAsset(context.getApplicationContext().getAssets(), "font/HelveticaNeueLTStd-LtEx.otf");
    }

    @Override
    public Object getChild(int groupPosition, int childPosititon) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .get(childPosititon);
    }

    @Override
    public long getChildId(int groupPosition, int childPosition) {
        return childPosition;
    }

    @Override
    public View getChildView(int groupPosition, final int childPosition,
            boolean isLastChild, View convertView, ViewGroup parent) {

        final clsTasks childText = (clsTasks) getChild(groupPosition, childPosition);

        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.list_tasks_done, null);
        }

        TextView txtListChild = (TextView) convertView
                .findViewById(R.id.lblListItemDone);

        txtListChild.setText(childText.getDescription());



        EditText txtTaskId = (EditText) convertView
                .findViewById(R.id.TaskIdDone);

        txtTaskId.setText(Integer.toString(childText.getTaskId()));

        TextView lblTaskTime = (TextView) convertView.findViewById(R.id.lblTaskDueTimeDone);

        if (childText.getTaskDate()==null)
        {
            //lblTaskTime.setText("Today");
        }
        else
        {
        lblTaskTime.setText( dateFormat1.format(childText.getTaskDate()) + " at " + dateFormat2.format(childText.getTaskDate()) );
        }



        if(ChildIds.contains(convertView)==false)
        {
        ChildIds.add(convertView);
        }

        txtListChild.setTypeface(tf, Typeface.NORMAL);
        lblTaskTime.setTypeface(tf, Typeface.NORMAL);

        return convertView;
    }

    @Override
    public int getChildrenCount(int groupPosition) {
        return this._listDataChild.get(this._listDataHeader.get(groupPosition))
                .size();
    }


    @Override
    public Object getGroup(int groupPosition) {
        return this._listDataHeader.get(groupPosition);
    }

    @Override
    public int getGroupCount() {
        return this._listDataHeader.size();
    }

    @Override
    public long getGroupId(int groupPosition) {
        return groupPosition;
    }

    @Override
    public View getGroupView(int groupPosition, boolean isExpanded,
            View convertView, ViewGroup parent) {
        clsTaskDoneDates headerTitle = (clsTaskDoneDates) getGroup(groupPosition);
        if (convertView == null) {
            LayoutInflater infalInflater = (LayoutInflater) this._context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = infalInflater.inflate(R.layout.list_folder_done, null);
        }

        TextView lblListHeader = (TextView) convertView
                .findViewById(R.id.folderNameDone);
        lblListHeader.setTypeface(tf, Typeface.NORMAL);
        lblListHeader.setText(dateFormat1.format(headerTitle.getTaskDate()));

        TextView lblFolderId = (TextView) convertView
                .findViewById(R.id.CurrentfolderIdDone);

        lblFolderId.setText(dateFormat1.format(headerTitle.getTaskDate()));



        return convertView;
    }


    @Override
    public boolean hasStableIds() {
        return false;
    }

    @Override
    public boolean isChildSelectable(int groupPosition, int childPosition) {
        return true;
    }



}

Answer 1

For adding and removing child views in group I created methods in adapter class and called it from my activity where i added or removed items in and from database.

public void removeChild(int groupPosition, int childPosition) {

        if (getChildrenCount(groupPosition)>0 && getChildrenCount(groupPosition)-1 >= childPosition )
        {
            Object task = this.getChild(groupPosition, childPosition);
            _listDataChild.remove(task);
            this.notifyDataSetChanged();
        }



    }

    public void AddChild(int groupPosition, clsTasks Newchild) {

        if (getGroupCount() > 0 && getGroupCount()-1 >= groupPosition )
        {           


                _listDataChild.get(this.getGroup(groupPosition)).add(Newchild);


            this.notifyDataSetChanged();
        }



    }