将CollectionView委托和数据源带出视图控制器

Question

I should start of with saying that I'm fairly new to swift. I'm trying to keep my view controllers as clean as possible. I created the following class

class AlbumArtist: UICollectionView, UICollectionViewDataSource, UICollectionViewDelegate {
var musicLib = musicLibrary()
var albumCollection: UICollectionView!
var layout: CustomCollectionViewFlow!

init(albumCView: UICollectionView){
    let nib = UINib(nibName: "CollectionViewCell", bundle: nil)
    albumCollection = albumCView

    musicLib.loadAlbums()
    layout = CustomCollectionViewFlow()
    print(layout)
    super.init(frame: albumCollection.frame, collectionViewLayout: layout)
    albumCollection.registerNib(nib, forCellWithReuseIdentifier: "item")
}

required init?(coder: NSCoder) {
    musicLib.loadAlbums()
    layout = CustomCollectionViewFlow()

    super.init(coder: coder)
}

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

func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return musicLib.getAlbumsCount()
}

func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
    let cell: CollectionViewCell = albumCollection.dequeueReusableCellWithReuseIdentifier("item", forIndexPath: indexPath) as! CollectionViewCell

    let objects = musicLib.getAlbums().objectAtIndex(indexPath.item) as! MPMediaItemCollection
    let repObjects = objects.representativeItem

    cell.lbl_Name.text = repObjects!.valueForProperty(MPMediaItemPropertyAlbumTitle) as? String

    let artwork = repObjects!.valueForProperty(MPMediaItemPropertyArtwork)

    let artworkImage = artwork?.imageWithSize(CGSize(width: 230, height: 230))

    if(artworkImage != nil){
        cell.img_artwork.image = artworkImage
    }
    else{
        cell.img_artwork.image = UIImage(named: "no_Artwork.png")
    }


    return cell
}

}

However I'm getting an error on my init method. Must call a designated initializer of the superclass 'UICollectionView'

I'm not sure if it is correct what I'm doing I couldn't find any examples on how to do this. So if I'm totally wrong I would love to hear what I need to do instead.

EDIT: I updated my code and it's running now. However it never comes to the delegate methods so the collection view is never being filled. I updated the code in the post with the new code. In my viewController i'm calling the class above like this in my viewDidLoad

AlbumArtist(albumCView: AlbumCollectionView)

I'm not sure if what I'm doing is correct

Answer 1

You're trying to inherit from the UICollectionView class, it not has any problem at all, but there are several ways to create a UICollectionView without inherit from the class UICollectionView :

• You can just create an @IBOutlet to a UICollectionView inside your UIViewController using Interface Builder.
• Create an UICollectionViewController to manage all using Interface Builder
• Create an UIContainerView inside your UIViewController to put inside an UICollectionViewController .

I hope this help you.

Answer 2

Apple defines a designated initializers as "the primary initializers for a class. A designated initializer fully initializes all properties introduced by that class and calls an appropriate superclass initializer to continue the initialization process up the superclass chain."

Basically for UICollectionView, instead of calling just super.init() which isn't a designated initializer, you should call super.init(frame: CGRect, collectionViewLayout: UICollectionViewLayout)