Dynamically Changing Keyboard Type for a UISearchBar

Question

I have an iPhone app that uses a UISearchBar and UISearchDisplayController. The search bar has three scope buttons. I would like the keyboard to

Answer 1

[searchBar reloadInputViews] 

and

[searchBar resignFirstResponder];
[searchBar becomeFirstResponder];

both can work, but the second method have more side effect, change firstResponder, can trigger keyboard's notification, so may affect other logic which depends on the keyboard's notification, and affect the view's frame which depend on keyboard frame's change