title: image scaling for UITabBar background image
body: <p>I've created UITabBarController in my application. </p>
  
  <p>Then in <code>viewDidLoad()</code> I want to change UITabBar background image. Here is the code I'm trying to make it works:</p>
  
  <pre><code>class MainTabBarController: UITabBarController {
  
      override func viewDidLoad() {
          super.viewDidLoad()
  
          UITabBar.appearance().translucent = false
          UITabBar.appearance().backgroundColor = UIColor.clearColor()
          UITabBar.appearance().backgroundImage = UIImage(named: "tabbar_background")
          UITabBar.appearance().contentMode = .ScaleAspectFit
      }
  }
  </code></pre>
  
  <p>But the result isn't correct (<a href="http://oi66.tinypic.com/nfny2s.jpg" rel="noreferrer">image</a>). Can someone help me to make it fill the entire tabbar frame?</p>