UIViews in swift - uiview

Question

All,
I have an image and then I display it on the screen and then I go to a function to blur the image. Then I run another function to add a box to it. but it doesn't show the blur and the box and this is because of the addSubView and the insertSubView - I presume. Basically I cannot put both the blur and the box on the view. If i uncomment out the addBox it doesn't show the blur. Can anyone help with my understanding of addSubView and InsertSubView (array).
Here is my code :
class ViewController: UIViewController {
var Box : UIView?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let bananaImage : UIImage = UIImage(named: "edify-backgound.png")
var imageV : UIImageView = UIImageView(image: bananaImage)
imageV.frame = CGRectMake(0, 0, bananaImage.size.width, bananaImage.size.height)
imageV.center = self.view.center
self.view.addSubview(imageV)
blur()
//addBox(CGRectMake(200, 300, 30, 30))
}
func addBox(location: CGRect)
{
let newBox = UIView(frame: location)
newBox.backgroundColor = UIColor.clearColor()
self.view.insertSubview(newBox, atIndex: 1)
Box = newBox
}
func blur()
{
var blur = UIVisualEffectView(effect: UIBlurEffect(style: .Light)) as UIVisualEffectView
blur.frame = self.view.frame
self.view.addSubview(blur)
}

Answer 1

Part of the problem is that you have no way of knowing whether addBox is doing anything or not. Here is your code:
let newBox = UIView(frame: location)
newBox.backgroundColor = UIColor.clearColor()
self.view.insertSubview(newBox, atIndex: 1)
A view that consists of nothing but a clear background color is completely invisible. So you see nothing - which, as Sherlock Holmes says, is exactly what you may expect to see.