View does not animate - swift

Question

I have a view, which shall move up like a drawer from the bottom of the screen. But it does not do anything. It just sits there =)
Can anyone please tell me, why it is doing that?
This is my code:
import UIKit
class InfoPopUpVC: UIViewController {
var superView: UIView!
var labelText: String!
let textLabel = UILabel()
let height = CGFloat(80)
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
UIView.animateWithDuration(0.4, animations: { () -> Void in
self.view.center.y = 50
})
}
override func viewDidLoad() {
super.viewDidLoad()
setupTextLabel()
view.frame = CGRectMake(0, superView.frame.maxY-height, superView.frame.width, height)
AnimationHelper.blurBackgroundForView(view)
view.backgroundColor = .greenColor()
}
func setupTextLabel(){
textLabel.text = labelText
textLabel.frame = CGRectMake(0, 0, view.frame.width, view.frame.height)
textLabel.numberOfLines = 3
textLabel.textAlignment = .Center
textLabel.frame.inset(dx: 10, dy: 8)
textLabel.sizeToFit()
textLabel.font = UIFont(name: "HelveticaNeue-Light", size: 17)
textLabel.textColor = .whiteColor()
view.addSubview(textLabel)
}
}

Answer 1

Try to put your code as follow inside viewDidAppear or viewWillAppear and with dispatch async. Otherwise your animation might not work.
override func viewDidAppear(animated: Bool) {
dispatch_async(dispatch_get_main_queue(), {
UIView.animateWithDuration(0.4, animations: { () -> Void in
self.view.center.y = 50
})
})
}

Answer 2

You cannot animate a frame or similar property, if the UIViewis constrained using autolayout.
You have two options:
Get rid of autolayout and animate the frames Directory
Use autolayout and animate the constraints (e.g. via outlets)
See the following links for examples:
How do I animate constraint-changes
IOS: ANIMATING AUTOLAYOUT CONSTRAINTS