title: Can I change the position of navigationbar item?
body: <p>Here is the snapshot:
  <img src="https://i.stack.imgur.com/qmXkR.png" alt="enter image description here"></p>
  
  <p>And the code is here:</p>
  
  <pre><code>UIButton *leftButton = [UIButton buttonWithType:UIButtonTypeCustom];
  leftButton.frame = CGRectMake(0.0f, 0.0f, 46.0f, 32.0f);
  [leftButton setBackgroundImage:[UIImage imageNamed:@"navi_register_up.png"] forState:UIControlStateNormal];
  [leftButton addTarget:self action:@selector(doRegister) forControlEvents:UIControlEventTouchUpInside];
  
  UIBarButtonItem *leftBarItem = [[UIBarButtonItem alloc] initWithCustomView:leftButton];
  self.navigationItem.leftBarButtonItem = leftBarItem;
  [leftBarItem release];
  </code></pre>
  
  <p>Is there any way to move the button up some px?
  Thank you:)</p>