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iosswiftxcodecollectionview

Constraint conflict because I can't deactivate constraint

I have a CollectionView and I want to size it's height dynamical with the content. I get an error because the setted constraint in the storyboard conflicts with the constraint setted in my code:

override func viewDidLoad() {
    super.viewDidLoad()
    view.addSubview(myCollectionView)
    //other constraints of collectionView
    collHeight = myCollectionView.heightAnchor.constraint(equalToConstant: 276)
    collHeight!.isActive = true
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
       //other stuff
        collHeight!.constant = collectionView.contentSize.height
        view.layoutIfNeeded()
 }

Error: https://pastebin.com/5yQh5hUP I can't delete the constraint with Entf on it. It only set's the number to 0. Can I deactivate it programmatically?

Solution

  • You have two options:

    1. Select your conflicting constraint and check the "Remove at build time" option

    enter image description here

    1. Instead of creating your constraint in the viewDidLoad function, you can make an outlet of the constraint and just set change it's constant.

      @IBOutlet weak var collectionViewHeightConstraint: NSLayoutConstraint!

override func viewDidLoad() {
   super.viewDidLoad()
   view.addSubview(myCollectionView)
   // Set the constant
   collectionViewHeightConstraint.constant = 276 // Change this as you wish
}