Why is UICollectionViewCell's outlet nil?

150
votes

I have created a custom UICollectionViewCell in Interface Builder, binded views on it to the class, and then when I want to use and set a string to the label on the string, tha label has a nil value.

override func viewDidLoad() {
    super.viewDidLoad()

    // Register cell classes
    self.collectionView.registerClass(LeftMenuCollectionViewCell.self, forCellWithReuseIdentifier: "ls")
}

override func collectionView(collectionView: UICollectionView!, cellForItemAtIndexPath indexPath: NSIndexPath!) -> UICollectionViewCell! {

    var cell: LeftMenuCollectionViewCell
    cell = collectionView.dequeueReusableCellWithReuseIdentifier("ls", forIndexPath: indexPath) as LeftMenuCollectionViewCell
    println(cell.label) // <- this is nil, why??
    cell.label.text = "asd"

    return cell
}

And the subclassed cell:

class LeftMenuCollectionViewCell: UICollectionViewCell {

    @IBOutlet weak var imageView: UIImageView!
    @IBOutlet weak var label: UILabel!
    @IBOutlet weak var activityIndicatorView: UIActivityIndicatorView!
}
8
iosswiftinterface-builderios8uicollectionviewcell
Is there a reason you're using the explicit "!" in addition to type names everywhere? Seems redundant, esp in the IBOutlets. The only place it might matter is where you dequeue the cell as LeftmenuCollectionViewCell, but you don't do it there.. Can you println or NSLog 'cell' itself? – mc01
If I remove "!" or use "?" in class definition, I get compiler error or crash. "!" is the default when you bind it. – János
ant the cell itself: <xxx.LeftMenuCollectionViewCell: 0x7aa7b320; baseClass = UICollectionViewCell; frame = (0 0; 180 50); layer = <CALayer: 0x7aa6f810>> – János
All outlets hooked up in IB? Do the other outlets work? Don't see any other obvious issues, sorry. – mc01
Basic example for setting up a Collection View – Suragch

8 Answers

322
votes

I am calling self.collectionView.registerClass(LeftMenuCollectionViewCell.self, forCellWithReuseIdentifier: "ls") again. If you are using a storyboard you don't want to call this. It will overwrite what you have in your storyboard.

If you still have the problem check wether reuseIdentifier is same in dequeueReusableCellWithReuseIdentifier and in storyboard.

55
votes

Just remove this line:

self.collectionView.registerClass(LeftMenuCollectionViewCell.self, forCellWithReuseIdentifier: "ls")
51
votes

If you are using xib, make sure that you have added this line of code to your viewdidload.

Objective C: 

[self.collectionView registerNib:[UINib nibWithNibName:@"MyCell" bundle:nil] forCellWithReuseIdentifier:@"MyCellIdentifier"];

Swift: 

collectionView.register(UINib(nibName:"MyCell", bundle: nil), forCellWithReuseIdentifier:"MyCellIdentifier")
17
votes

Gotta register that nib guys!

collectionView.register(UINib(nibName: "CustomCell", bundle: nil), forCellWithReuseIdentifier: "CustomCellId")
10
votes

Looks like there's two ways to register and I was using the wrong one the first. I have a custom xib view so registered with the second option, and we have data!

1:

collectionView?.register(YourItemClassName.self, forCellWithReuseIdentifier: "yourIdentifier")

2: 

collectionView?.register(UINib(nibName: "YourItemClassName", bundle: nil), forCellWithReuseIdentifier: "yourIdentifier")
0
votes

I had a similar problem, but my mistake was that I didn't delegate CollectionViewCell to be able to change the label text..

0
votes

I think that best solution is to directly use from storyboard where add a CollectionView, in alternative you need to remove a CollectionViewCell from your CollectionView in storyboard and register a cell with the following command:

collectionView?.register(UINib(nibName: "YourItemClassName", bundle: nil), forCellWithReuseIdentifier: "yourIdentifier")

0
votes

You didn't register your cell,

fileprivate let yourIdentifier = ""yourIdentifier"
super.viewDidLoad() {

//here you need to register cell collectionView?.register(NameOfYourClass.self, forCellWithReuseIdentifier: "yourIdentifier") }