How to update all the children items of listview?

Question

public class ListAdapter extends ArrayAdapter { Context context; // Main Context ArrayList data = new ArrayList(); // main textview data

/* Constructor */
public ListAdapter(Context context, ArrayList<String> dataItem) {
    super(context, R.layout.list_item, dataItem);
    this.data = dataItem;
    this.context = context;
}

/* Contains the all items */
public class ViewHolder {
    TextView text;
    CheckBox checkBox;
    TextView time;
}

/* Get the current item view */
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    ViewHolder viewHolder;
    if (convertView == null) {
        LayoutInflater inflater = LayoutInflater.from(context);
        convertView = inflater.inflate(R.layout.list_item, null);
        viewHolder = new ViewHolder();
        viewHolder.text = (TextView) convertView
                .findViewById(R.id.childTextView);
        viewHolder.checkBox = (CheckBox) convertView
                .findViewById(R.id.checkBox);
        viewHolder.checkBox.setVisibility(View.GONE);
        viewHolder.time = (TextView) convertView.findViewById(R.id.textTime);
        convertView.setTag(viewHolder);
    } else {
        viewHolder = (ViewHolder) convertView.getTag();
    }
    final String temp = getItem(position);
    viewHolder.text.setText(temp);

    viewHolder.checkBox.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            if (checkBoxClickListener != null) {
                checkBoxClickListener.onCheckBoxClickListener(position, temp);
            }

        }
    });
    return convertView;
}

CheckBoxClickListener checkBoxClickListener;

public interface CheckBoxClickListener {
    public void onCheckBoxClickListener(int position, String value);
}

public void setCheckBoxClickListener(CheckBoxClickListener listener) {
    this.checkBoxClickListener = listener;
}

}

This is my adapter. At first, checkboxes are invisible and after long clicking I wanna make the checkboxes visible.

In my mainactivity,

for(int i = 0; i < listView.getAdapter().getCount(); i++) {
View v = getViewByPosition(i, listView);
ListAdapter.ViewHolder view = (ListAdapter.ViewHolder) v.getTag();
view.checkBox.setVisibility(state);
}
adapter.notifyDataSetChanged();
listview.invalidateViews();

public View getViewByPosition(int pos, ListView listView) {
final int firstListItemPosition = listView.getFirstVisiblePosition();
final int lastListItemPosition = firstListItemPosition + listView.getChildCount() - 1;

if (pos < firstListItemPosition || pos > lastListItemPosition ) {
    return listView.getAdapter().getView(pos, null, listView);
} else {
    final int childIndex = pos - firstListItemPosition;
    return listView.getChildAt(childIndex);
}

}

I tried like this, but checkboxes in unvisible items(by scrolling) are not visible yet.

Can anybody solve this problem to help me out?