uitableview reloadData - how do we table refresh is done?

I want to do a reloadData on a UITableView and after the table refresh is done, 开发者_StackOverflow中文版I want a delegate method to be called when I can know that the refresh is done. How do we know that ?

-reloadData blocks execution—your code won't continue past that call unless you're doing it on a separate thread. It should only be configuring nine cells or so at most; is there some reason you expect that to take a long time?