title: Cannot set searchBar as firstResponder
body: <p>I have a searchBar I'm setting in a tableviewcontroller. i've referenced this similar question <a href="https://stackoverflow.com/questions/27451088/uisearchbar-cannot-become-first-responder-after-uitableview-did-re-appear">UISearchBar cannot become first responder after UITableView did re-appear</a> but am still unable to set it as first responder. 
  In .h file:</p>
  
  <pre><code>@property (strong, nonatomic) UISearchController *searchController;
  @property (strong, nonatomic) IBOutlet UISearchBar *searchBar;
  </code></pre>
  
  <p>In view didload:</p>
  
  <pre><code>self.searchController = [[UISearchController alloc]initWithSearchResultsController:nil];
  self.searchController.searchResultsUpdater = self;
  self.searchController.dimsBackgroundDuringPresentation = NO;
  self.searchController.hidesNavigationBarDuringPresentation = NO;
  
  self.searchController.searchBar.frame = CGRectMake(self.searchController.searchBar.frame.origin.x, self.searchController.searchBar.frame.origin.y, self.searchController.searchBar.frame.size.width, 44.0);
  self.tableView.tableHeaderView = self.searchController.searchBar;
  </code></pre>
  
  <p>And in viewDidAppear:</p>
  
  <pre><code>-(void)viewDidAppear:(BOOL)animated {
    [self.searchController setActive:YES];
    [self.searchController.searchBar becomeFirstResponder];
    [super viewDidAppear:animated];
  }
  </code></pre>
  
  <p>When I segue to the view the searchBar animates, but no keyboard appears.</p>