在UITableView底部添加活动指示器？

I have UITableview with pagination like first will get 20 objects from server and will populate in UITableView then when it reaches last row need to make another service call to get next 20 objects.My problem is I need to add activity indicator at bottom of my table and should say "Loading",User can scroll to up to view current objects but should not scroll down.Is there any custom control? Is there any best way to achieve it?.Thanks in advance.I have UITableview with pagination like first w