iosswiftios-autolayout

Removing constraints that were added programatically

I read many topics about how to remove constraints that were added through the storyboard, drag outlet and then remove etc. but how I can remove constraints that were added programmatically? For example

firstView.topAnchor.constraints(equalTo: secondView.bottomAnchor, constant: 15).isActive = true

how can I deactivate it and then enable it again if needed. Maybe it should be something like?

firstView.removeConstraint(firstView.topAnchor.constraints(equalTo: secondView.bottomAnchor))
Solution

  • You should assign your constraint to a property in your ViewController. And then set .isActive to false instead of true.

    Your code should look like this:

    let myConstraint = firstView.topAnchor.constraint(equalTo: secondView.bottomAnchor, constant: 15)

    Now, to activate it: 

    myConstraint.isActive = true

    And to disable it:

    myConstraint.isActive = false