How to set background image for UINavigationBar on different iOS Devices

Question

I want to set full image on UINavigationBar, for this I have:

@2x image (640 x 128)
@3x image (960 x 192)

Below Screenshot is the

Answer 1

Create a resizeable image. So the image will be scaled vertically and horizontally to fit the navigation bar including the status bar.

For Swift 3:

if let image = UIImage(named: "imagefile") {
   let backgroundImage = image.resizableImage(withCapInsets: UIEdgeInsets.zero, resizingMode: .stretch)
   self.navigationController?.navigationBar.setBackgroundImage(backgroundImage, for: .default)
}

or

if let image = UIImage(named: "imagefile") {
   let backgroundImage = image.resizableImage(withCapInsets: UIEdgeInsets.zero, resizingMode: .stretch)
   UINavigationBar.appearance().setBackgroundImage(backgroundImage, for: .default)
}