title: Custom UIBarButtonItem with interface builder
body: <p>I used <em>pushViewController:animated:</em> method in A UIViewController to go to B UIViewController, and the two UIViewController had selfs xib file.</p>
  
  <p>In system default, I did not need to change anything and I can go back A UIViewController from B UIViewController.</p>
  
  <p>But I want to custom my back button, I use the solution like the follow code:</p>
  
  <pre><code>- (void)initBarButton {
      UIBarButtonItem *cancelButton = [[UIBarButtonItem alloc] initWithTitle:@"Cancel" style:UIBarButtonItemStyleDone target:self action:@selector(cancel)];
  
      self.navigationItem.leftBarButtonItem = cancelButton;
  
      UIBarButtonItem *updateButton = [[UIBarButtonItem alloc] initWithTitle:@"Update" style:UIBarButtonItemStyleDone target:self action:@selector(save)];
  
      self.navigationItem.rightBarButtonItem = updateButton;
  }
  
  - (void)cancel {
      [self.navigationController popViewControllerAnimated:YES];
  }
  </code></pre>
  
  <p>Just like this, but I want to change that in interface builder to modified the xib file to do this. I try to use that like:</p>
  
  <p><img src="https://i.stack.imgur.com/z098A.png" alt="enter image description here"></p>
  
  <p>But the system default navigation bar is cover, when I hide the system default bar, the swipe gesture(go back like pop action) also be removed.</p>
  
  <p>Is any possible way to do what I want? </p>
  
  <p>BTW, I used the navigation bar in interface builder with auto layout, how can I let it look like system default navigation bar like this(fill the status bar gap)?</p>
  
  <p><img src="https://i.stack.imgur.com/52cEk.png" alt="enter image description here"></p>