如何在检索ListView的项目时显示"正在加载..."文本

public class MyAdapter extends BaseAdapter {
    private List<String> dataList;
    private Context context;
    private boolean isLoading;

    public MyAdapter(Context context, List<String> dataList) {
        this.context = context;
        this.dataList = dataList;
    }

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

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

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;
        if (convertView == null) {
            convertView = LayoutInflater.from(context).inflate(R.layout.list_item, parent, false);
            viewHolder = new ViewHolder();
            viewHolder.textView = convertView.findViewById(R.id.textView);
            viewHolder.loadingTextView = convertView.findViewById(R.id.loadingTextView);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        if (isLoading && position == getCount() - 1) {
            viewHolder.loadingTextView.setVisibility(View.VISIBLE);
            viewHolder.textView.setVisibility(View.GONE);
        } else {
            viewHolder.loadingTextView.setVisibility(View.GONE);
            viewHolder.textView.setVisibility(View.VISIBLE);
            viewHolder.textView.setText(dataList.get(position));
        }

        return convertView;
    }

    public void setLoading(boolean isLoading) {
        this.isLoading = isLoading;
        notifyDataSetChanged();
    }

    static class ViewHolder {
        TextView textView;
        TextView loadingTextView;
    }
}

myAdapter.setLoading(false);