title: About hide toolbar in iphone app
body: <p>I have a navigationController which root viewController has no toolbar,but the root viewController navigates to a viewController which has a always visible toolbar.I must assure the root viewController's toolbar is hidden whether it is presented first or its above viewController is poped in the navigationController stack.So,I use the following code in the root viewController:</p>
  
  <pre><code>- (void)viewWillAppear:(BOOL)animated{
      [super viewWillAppear:animated];
      [self.navigationController setToolbarHidden:YES animated:YES];
  }
  </code></pre>
  
  <p>is this the best sulotion?or I should use "hidesBottomBarWhenPushed" etc?</p>