CollectionViewController

import UIKit

private let reuseIdentifier = "cell"

class ControllerListCollectionView: UICollectionViewController, UICollectionViewDelegateFlowLayout {

    private var selectedZone: ZoneListBrain.zone?
    private var controllerKeys: [String]?

    override func viewDidLoad() {
        super.viewDidLoad()

        let aFlowLayout = UICollectionViewFlowLayout()
        aFlowLayout.itemSize = CGSizeMake(100, 22)
        self.collectionView!.collectionViewLayout = aFlowLayout
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    override func numberOfSectionsInCollectionView(collectionView: UICollectionView) -> Int {
        return 1
    }

    override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {        if selectedZone?.controller != nil {
            return (selectedZone?.controller?.count)!
        } else {
        return 0//초기값
        }
    }
    override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as! ControllerListCell 
        cell.backgroundColor = UIColor.redColor()
        if controllerKeys != nil {
            cell.listLabel.text = controllerKeys![indexPath.item]
            cell.listLabel.textAlignment = NSTextAlignment.Center
            return cell
        }
        return cell
    }

    func GetZoneControllerList(select: ZoneListBrain.zone) {
        selectedZone = select
        controllerKeys = [String](selectedZone!.controller!.keys)
        self.collectionView?.reloadData()//오류 발생지점!

    }
}

오류내용

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'UICollectionView must be initialized with a non-nil layout parameter'

질문입니다. collectionView?.reloadData() 만 사용을 하면 위와같은 오류가 발생합니다. 저는 위와같은 오류로 2주일 가까이 고민하고 있지만 해결을 못하고 있습니다.... 꼭 해결하고 싶습니다. 그리고 collectionView 라고 하는것은 어디에 있는것인가요? 어디에 있는것이길래 이렇게 불러와서 사용을 하는것인지도 궁금합니다.