Set Image Underlay of Transparent Navigation Bar and Status Bar in Swift iOS 8

I have tried same code as you provided:

override func viewDidLoad() {
    super.viewDidLoad()
    self.navigationController!.navigationBar.setBackgroundImage(UIImage(), forBarMetrics: .Default)
    self.navigationController!.navigationBar.shadowImage = UIImage()
    self.navigationController!.navigationBar.translucent = true
}

And it is working fine and you can see result here:

Check my sample project and find out what are you missing.

Hope it will help.

I solved this by setting transparent UIColor for status bar background.

    guard  let statusBar = UIApplication.sharedApplication().valueForKey("statusBarWindow")?.valueForKey("statusBar") as? UIView else {
                return
            }
            statusBar.backgroundColor = UIColor(red: 2, green: 200.0, blue: 200, alpha: 0) // color value has no effect. Only alpha value is needed to make it transparent

If you are not using the default navigation bar, then shift your background image view (which is going to visible below the status bar) 20px up from the top constraint, then clear your status bar background color using:

 override func viewDidLoad() {
    super.viewDidLoad()

    let statusBar = UIApplication.shared.value(forKeyPath: "statusBarWindow.statusBar") as? UIView
        statusBar?.backgroundColor = UIColor.clear
}

If you want to change the status bar item's color to white then use:

 override var preferredStatusBarStyle: UIStatusBarStyle {
    return .lightContent
}

The output will be