title: iOS self.navigationController.toolbar position to top doesn't change
body: <p>I am trying to change <code>self.navigationController.toolbar</code> position to top instead of a bottom.</p>
  
  <p>ViewController.h</p>
  
  <pre><code>#import &lt;UIKit/UIKit.h&gt;
  
  @interface ViewController : UIViewController &lt;UIToolbarDelegate, UIBarPositioningDelegate&gt;
  
  @end
  </code></pre>
  
  <p>ViewController.m</p>
  
  <pre><code>#import "ViewController.h"
  
  @interface ViewController ()
  
  @end
  
  @implementation ViewController
  
  // View did load
  - (void)viewDidLoad
  {
      // Superclass view did load method call
      [super viewDidLoad];
  
      // UIToolbarDelegate
      self.navigationController.toolbar.delegate = self;
  }
  
  - (void)viewDidLayoutSubviews
  {
      self.navigationController.toolbarHidden = NO;
      self.navigationController.toolbar.frame = CGRectMake(self.navigationController.toolbar.frame.origin.x, 64.0f, self.navigationController.toolbar.frame.size.width, self.navigationController.toolbar.frame.size.height);
  
      UISegmentedControl *segmentedControl = [[UISegmentedControl alloc] initWithItems:@[@"First", @"Second"]];
      segmentedControl.frame = CGRectMake(50.0f, 10.0f, 220.0f, 24.0f);
      segmentedControl.selectedSegmentIndex = 1;
      [self.navigationController.toolbar addSubview:segmentedControl];
  }
  
  - (UIBarPosition)positionForBar:(id &lt;UIBarPositioning&gt;)bar
  {
      return UIBarPositionTopAttached;
  }
  
  @end
  </code></pre>
  
  <p>The position changes at first, but later gets back to the bottom. Please, help me!</p>