首先萌踱，在 viewcontroller 上先加個(gè)UICollectionViewDelegateFlowLayout
如下：
class TemplateCollectionViewController: UICollectionViewController,UICollectionViewDelegateFlowLayout {
}
實(shí)現(xiàn)下面兩個(gè)layout 的 delegate 方法即可
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let padding: CGFloat = 20
let collectionViewSize = collectionView.frame.size.width - 3*padding
return CGSize(width: collectionViewSize/2, height: **)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
return UIEdgeInsetsMake(0, 20, 0, 20)
}