baseadapter listview错误

public int getCount() {
// TODO Auto-generated method stub
return productlist.size();
}


@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return productlist.get(position);
}


@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;

}

返回值需要写出来 否则会有错误