Ios 集合视图顶部的奇怪间隙

不知道发生了什么事。这可能是iOS 8上的collectionView错误吗？顶部的黑色不应该在那里

视图控制器代码：

class SearchViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout {

    @IBOutlet var collectionView: UICollectionView!

    // MARK: - VC Lifecycle
    override func viewDidLoad() {
        super.viewDidLoad()

        var viewNib = UINib(nibName: "SearchFiltersCollectionReusableView", bundle: nil)
        collectionView.registerNib(viewNib, forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "filter")

        var viewNib2 = UINib(nibName: "SearchResultCollectionViewCell", bundle: nil)
        collectionView.registerNib(viewNib2, forCellWithReuseIdentifier: "searchCell")
        // Do any additional setup after loading the view.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    // MARK: - CV Datasource
    func numberOfSectionsInCollectionView(collectionView: UICollectionView!) -> Int {
        return 2
    }

    func collectionView(collectionView: UICollectionView!, numberOfItemsInSection section: Int) -> Int {

        var itemsCount = section == 1 ? 10 : 0
        return itemsCount
    }

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

        var cell = collectionView.dequeueReusableCellWithReuseIdentifier("searchCell", forIndexPath: indexPath) as UICollectionViewCell

        return cell
    }

    // MARK: - CV Delegate
    func collectionView(collectionView: UICollectionView!, viewForSupplementaryElementOfKind kind: String!, atIndexPath indexPath: NSIndexPath!) -> UICollectionReusableView! {

        var section = indexPath.section
        var identifier = indexPath.section == 0 ? "nav" : "filter"

        var view = collectionView.dequeueReusableSupplementaryViewOfKind(UICollectionElementKindSectionHeader, withReuseIdentifier: identifier, forIndexPath: indexPath) as UICollectionReusableView
        return view
    }
    // MARK: - CV DelegateFlow
    func collectionView(collectionView: UICollectionView!, layout collectionViewLayout: UICollectionViewLayout!, sizeForItemAtIndexPath indexPath: NSIndexPath!) -> CGSize {

        var width = collectionView.bounds.size.width
        return CGSizeMake(width, 70)
    }

    func collectionView(collectionView: UICollectionView!, layout collectionViewLayout: UICollectionViewLayout!, referenceSizeForHeaderInSection section: Int) -> CGSize {

        var width = collectionView.bounds.size.width
        var height : CGFloat = section == 0 ? 240.0 : 70.0

        return CGSizeMake(width, height)
    }


}

---

尝试将视图控制器

automaticallyAdjustsScrollViewInsets

属性设置为

NO