How to change bottom layout constraint in iOS, Swift

Question

I have scroll view as @IBOutlet

@IBOutlet weak var mainScrollView: UIScrollView!

I want to change the

\"Bottom space to: B         


        

Answer 1

Create an IBOutlet for your constraint:

@property (weak, nonatomic) IBOutlet NSLayoutConstraint *bottomContraint;

And when you need to change it call:

bottomContstraint.constant = //your value
view.layoutIfNeeded()

Also you can animate constraint change like that:

bottomContstraint.constant = //your value

UIView.animateWithDuration(0.5, animations: {
  self.view.layoutIfNeeded()
})