UICollectionView基本使用

每次用都要搜索一圈相关用法,实在是不胜其烦,这里记录一下.

定义好Identifier

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

UICollectionViewFlowLayout

collectionView的布局样式类,这个玩意设置的灵活得多,不仅仅是布局,还可以实现很多奇特的效果,这里关注基本用法,在此就不再赘述.

初始化

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

collectionView.delegate = self

注册headerview和cell

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

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

相关协议

UICollectionViewDelegate,

UICollectionViewDataSource,

UICollectionViewDelegateFlowLayout

相关代理

collectionView datasource:

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

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

    return 0

}

collectionView delegate:

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

CollectionView DelegateFlowLayout:

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

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