how to set a background image as colorWithPatternImage in swift

I prefer to this one:

let backgroundImage = UIImageView(frame: UIScreen.mainScreen().bounds)
backgroundImage.image = UIImage(named: "background.png")
self.view.insertSubview(backgroundImage, atIndex: 0)

Since setting image as backgroundColor would make it a litte blurry.

Edited @User9527 's answer a bit. Not sure why it was down voted.. Worked great for me. Just added my own custom frame.

let frame = CGRectMake(10, 55, 45, 45)
let backgroundImage = UIImageView(frame: frame)
backgroundImage.image = UIImage(named: "bg_image")
self.view.insertSubview(backgroundImage, atIndex: 0)

Refer to the UIColor documentation.

In Swift, you have to call a convenience initializer. This is because in Swift, all Objective-C class methods which return an instance of their class become convenience initializers.

Here's how it looks in Swift:

 self.view.backgroundColor = UIColor(patternImage: UIImage(named: "background.png"))

+ (UIColor *)colorWithPatternImage:(UIImage *)image returns a UIColor instance, so it will become a convenience initializer in Swift. Similarly, UIImage imageNamed: becomes init(patternImage image: UIImage!).