IOS customview removing the subviews - ios

Question

I am trying to apply background Image to all my screens in my iOs application.
My initial screen is a Registration screen where i want to apply the background image, the registration screen is as shown below:
I am using a custom UIView from xib file to apply the background image.
But after applying the background image it only shows the background image on the Registration screen and removes the login controls. I dont know why.
Following is the registration screen after applying the image background.
One more thing, I can see the background image only on the run time not in the Storyboard.
Following is my implementation
I have created one .xib file having a simple UIView, this UIView would serve as a master view in all my application. To obtain the UIView from nib file and to apply further settings I am using a custom UIView class. In this custom UIView class I am applying the background image on the UIView obtained from the nib file. As you can see above I am applying this custom UIView class to the Registration screen UIView. Following is the code as shown below:
class BackgroundMap: UIView {
var view: UIView!
override init(frame: CGRect) {
super.init(frame: frame)
view = loadViewFromNib ()
view.frame = bounds
view.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
view.translatesAutoresizingMaskIntoConstraints = true
view.backgroundColor = UIColor(patternImage: UIImage(named: "MapWantd")!)
self.addSubview(view)
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
view = loadViewFromNib ()
view.frame = bounds
view.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
view.translatesAutoresizingMaskIntoConstraints = true
view.backgroundColor = UIColor(patternImage: UIImage(named: "MapWantd")!)
self.addSubview(view)
}
func loadViewFromNib() ->UIView {
let bundle = NSBundle(forClass: self.dynamicType)
let nib = UINib(nibName: "BackgroundMap", bundle: bundle)
let view = nib.instantiateWithOwner(self, options: nil)[0] as! UIView
return view
}
}