UIcollectionView基本使用

使うたびに1周検索しなければならない使い方は、本当に煩わしいので、ここに記録しておきます.
Identifierを定義

private let cellReuseIdentifier = "tagCollectionViewCell"
private let headerReuseIdentifier = "headerReuseIdentifier"

UICollectionViewFlowLayout
collectionViewのレイアウトスタイルクラスは、レイアウトだけでなく、多くの奇抜な効果を実現するために、この基本的な使い方に注目し、ここでは説明しない.
初期化

let layout = UICollectionViewLayout()
    
let collectionView = UICollectionView(frame: CGRectZero, collectionViewLayout: layout)
    
collectionView.dataSource = self

collectionView.delegate = self

headerviewとcellの登録

collectionView.registerNib(UINib.init(nibName: "TeaFriendsTagCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: cellReuseIdentifier)

collectionView.registerClass(headerView.classForCoder, forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: headerReuseIdentifier)

関連プロトコル

UICollectionViewDelegate,

UICollectionViewDataSource,

UICollectionViewDelegateFlowLayout

関連エージェント

collectionView datasource:

//     
func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return 0
}

//sections  
func numberOfSectionsInCollectionView(collectionView:UICollectionView) ->Int {

    return 0

}

collectionView delegate:

//  cell
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
    
}

CollectionView DelegateFlowLayout:

//headerview Size
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
    
    return CGSizeMake(ScreenWidth, 80 * HEIGHT_SCALE)
}

//   headerview
func collectionView(collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, atIndexPath indexPath: NSIndexPath) -> UICollectionReusableView {
    
    if kind == UICollectionElementKindSectionHeader {
        headerView = collectionView.dequeueReusableSupplementaryViewOfKind(kind, withReuseIdentifier: headerReuseIdentifier, forIndexPath: indexPath) as! TagHeaderCollectionReusableView
        headerView.pagedView.delegate = self
        
        return headerView
    }else {
        
        return UICollectionReusableView()
    }
}

//cell Size
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
    let w = (ScreenWidth - 30)/2
    return CGSizeMake(w, w)
}