Make navigation bar transparent regarding below image in iOS 8.1

Question

I try to set my navigation bar transparent regarding a image below this, something like the following image :

Answer 1

just checked on the 8.1 simulator and got very similar result to your picture

    let bar:UINavigationBar! =  self.navigationController?.navigationBar

    bar.setBackgroundImage(UIImage(), forBarMetrics: UIBarMetrics.Default)
    bar.shadowImage = UIImage()
    bar.backgroundColor = UIColor(red: 0.0, green: 0.3, blue: 0.5, alpha: 0.3)

main point here is background color with alpha.

Check attached image, maybe I missed something?