CODEWITHSUNDEEP
iosswiftautolayout
Steve
Steve

Reputation: 55635

UICollectionView and AutoLayout

I'm trying to create a UICollectionView whose width/height and coordinates are defined using AutoLayout (using SnapKit). When using the default UICollectionView constructor it fails with the following reason:

reason: 'UICollectionView must be initialized with a non-nil layout parameter'

The only constructor that allows a layout to be passed in, also requires a frame, so I tried using CGRectZero as the value for the frame like so: 

collectionView = UICollectionView(frame: CGRectZero, collectionViewLayout: layout)

I then used SnapKit to setup the constraints like so:

collectionView?.snp_makeConstraints { make -> Void in
        make.width.equalTo(view)
        make.height.equalTo(300)
        make.top.equalTo(someOtherView)
    }

However, when doing so the UICollectionView is never rendered. In fact, I do not see the data source being called at all.

Any thoughts on how to use AutoLayout with a UICollectionView or what I might be doing wrong?

Upvotes: 3

Views: 2068

Answers (1)

DevAndArtist
DevAndArtist

Reputation: 5159

This following code works just fine for me and I got a red and empty collection view.

Xcode 7 beta 4 - Swift 2.0 - AutoLayout syntax from iOS 9

override func viewDidLoad() {

    super.viewDidLoad()

    let collectionView = UICollectionView(frame: CGRectZero, collectionViewLayout: UICollectionViewLayout())
    collectionView.translatesAutoresizingMaskIntoConstraints = false
    collectionView.backgroundColor = UIColor.redColor()

    self.view.addSubview(collectionView)

    collectionView.widthAnchor.constraintEqualToAnchor(self.view.widthAnchor).active = true
    collectionView.heightAnchor.constraintEqualToConstant(300).active = true
    collectionView.topAnchor.constraintEqualToAnchor(self.view.topAnchor).active = true
}

I never used SnapKit but I do know it. The syntax provided in my code is almost the same as in your example. So it is only a clue that something is wrong with SnapKit or how you use it.

I hope this can help you somehow.

Upvotes: 7

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