Reuse Code to set image - xcode

Question

i´m developing an app that has a lot of view controllers and did set the back ground image with code, but i have to copy and paste that block of code in every view controller, how can i type it once and call it to reuse the code in every view controller..Thanks A lot.
var imageView: UIImageView!
let image = UIImage(named: "backGroundImage.png")!
override func loadView() {
super.loadView()
self.imageView = UIImageView(frame: CGRectZero)
self.imageView.contentMode = .ScaleAspectFill
self.imageView.image = image
self.view.addSubview(imageView)
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
self.imageView.frame = self.view.bounds
}

Answer 1

What you can do is make a parent UIViewController class and have all of your view controllers inherit from that class. Somethig like this:
class MyParentViewController: UIViewController {
var imageView: UIImageView!
let image = UIImage()
override func viewDidLoad() {
super.viewDidLoad()
self.imageView = UIImageView(frame: CGRectZero)
self.imageView.contentMode = .ScaleAspectFill
self.imageView.image = image
self.view.addSubview(imageView)
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
self.imageView.frame = self.view.bounds
}
}
And then your child view controllers that enherit from this class would look something like this:
class MyViewController: MyParentViewController {
overide func viewDidLoad() {
image = UIImage(named:"My image name")
super.viewDidLoad()
}
}
Now, here is really the way you should do it
However, having multiple view controllers that are all the same probably isnt a good idea. I would just keep only the parent view controller (rename it obviously) and just change the value of "image" in the segue that leads to the view to whatever image you want. This would eliminate the need to have a ton of view controllers, and will make it easier to add more images in the future if you want.

Answer 2

Here's how I would do it:
protocol ImageViewBackground {
var backgroundImageView: UIImageView? {get set}
mutating func setBackgroundImage(image: UIImage)
}
extension ImageViewBackground where Self: UIViewController {
mutating func setBackgroundImage(image: UIImage) {
let backgroundImageView = self.backgroundImageView ?? setupImageView()
backgroundImageView.image = image
}
mutating func setupImageView() -> UIImageView {
let imageView = UIImageView(frame: self.view.frame)
imageView.contentMode = .ScaleAspectFill
view.addSubview(imageView)
backgroundImageView = backgroundImageView
return imageView
}
}
Then just make any UIViewController adhere to the protocol like so:
class ViewController: UIViewController, ImageViewBackground {
var backgroundImageView: UIImageView?
}
Then you can call setBackgroundImage from anywhere in your VC without having to make a generic subclass just for the background image.