Designing UICollectionViewCell in storyboard

Question

I have never used UICollectionViewControllers, and I thought that they were somewhat similar to UITableViewControllers, but to my surprise, I cannot add UI elements to my custom UICollectionViewCells in the same way as I do with custom UITableViewCells.

In fact, I can add labels, buttons, etc. in the Interface Builder, but when I run the application, the cells appear empty.

I have registered the cell class during the viewDidLoad method by calling (void)registerClass:(Class)cellClass forCellWithReuseIdentifier:(NSString *)identifier, and I've checked that I am returning a valid instance of UICollectionViewCellin the (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath method.

What am I doing wrong?

Answer 1

My full explanation is here.

Create a custom class for the UICollectionViewCell:

import UIKit
class MyCollectionViewCell: UICollectionViewCell {

    // have outlets for any views in your storyboard cell
    @IBOutlet weak var myLabel: UILabel!
}

In the storyboard make the cell use this class

And set the Identifier for the cell

Don't use the registerClass...forCellWithReuseIdentifier in viewDidLoad. But you will refer to it in collectionView...cellForItemAtIndexPath:

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

    // get a reference to our storyboard cell
    let cell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as! MyCollectionViewCell

    // Use the outlet in our custom class to get a reference to the UILabel in the cell
    cell.myLabel.text = self.items[indexPath.item]
    cell.backgroundColor = UIColor.yellowColor()

    return cell
}

Hook up the outlets from the Views in your storyboard cell to the MyCollectionViewCell class.

Answer 2

@Suragch is spot on. I had this problem too: my UICollectionViewCell prototype's contents did not show in the cell when it got drawn.

The critical line is: "Don't use the registerClass...forCellWithReuseIdentifier in viewDidLoad". Really, don't. Not just "there is no need to", but "if you do register, it will stop your cell prototype from loading properly".

This only applies to Storyboard-based code, not .xib-based.