How to set background image in swift?

Question

I am trying to set aground image to my ViewController in swift language.

I am using the following code :

self.view.backgroundColor = UIColor(patternImage: UIImage(named:”bg.png")!)

But the app is getting crash.It is showing the error like

“fatal error: unexpectedly found nil while unwrapping an Optional value”(Because of the “!”)

Answer 1

That error is thrown because the image "bg.png" does not exist. Usually when you import images to the Assets.xcassets folder, the file extension is removed. So try the following:

self.view.backgroundColor = UIColor(patternImage: UIImage(named:"bg")!)

You will notice that the background will not look as expected, you need to do the following as explained here:

     UIGraphicsBeginImageContext(self.view.frame.size)
    UIImage(named: "bg")?.draw(in: self.view.bounds)
    let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
    UIGraphicsEndImageContext()
    self.view.backgroundColor = UIColor(patternImage: image)

Answer 2

Try this Swift4:

let backgroundImage = UIImageView(frame: UIScreen.main.bounds)
backgroundImage.image = UIImage(named: "bg.png")
backgroundImage.contentMode = UIViewContentMode.scaleAspectFill
self.view.insertSubview(backgroundImage, at: 0)

Answer 3

Update for swift3 :

    UIGraphicsBeginImageContext(self.frame.size)

    UIImage(named: "bg").draw(in: self.bounds)

    let image: UIImage = UIGraphicsGetImageFromCurrentImageContext()!

    UIGraphicsEndImageContext()

    backgroundColor = UIColor(patternImage: image)