How to change Auto Layout constraints after they are set when using constraintEqualToAnchor()?

Question

I try to set up a view with AutoLayout constraints by using constraintEqualToAnchor():

override func viewDidLoad() {
    super.viewDidLoad()

    le         


        

Answer 1

Here is example with if statement modifying a StackView and View when a segmented clicked:

if (sender as AnyObject).selectedSegmentIndex == 0{
    // Shrink the white view and stack view
    heightConstraintView = containerView.heightAnchor.constraint(equalToConstant: 100)
    heightConstraintView?.isActive = true
    heightConstraintStackView = stackView.heightAnchor.constraint(equalToConstant: 100)
    heightConstraintStackView?.isActive = true
} else {
    // Before returning back the white view and stack view DEACTIVATE teh previous constraints
    heightConstraintView?.isActive = false
    heightConstraintStackView?.isActive = false
    // Returning back the white view and stack view to normal size
    heightConstraintView = containerView.heightAnchor.constraint(equalToConstant: 200)
    heightConstraintView?.isActive = true
    heightConstraintStackView = stackView.heightAnchor.constraint(equalToConstant: 200)
    heightConstraintStackView?.isActive = true
}