title: How to hide the tabBar when push a view?
body: <p>My application is a Tabbed Application, and it have several controllers under the tabBarController. One controller is a navigationController, and its root view is a table view. When I click a row of the table view, another view will be pushed in. 
  So the question is that when the view is pushed in, how can I hide the tabBar at the bottom?
  Besides, I also want to add another tabBar into the pushed view, so I need to alloc a UITabBar or UITabBarController? Or there is another way? Thank you!</p>