我正在创建带有节标题的自定义flowLayout。这是我的flowLayout.swiftimportUIKitclassFlowLayout:UICollectionViewFlowLayout{overridefunclayoutAttributesForElementsInRect(rect:CGRect)->[UICollectionViewLayoutAttributes]?{//letattributesForElementsInRect=super.varnewAttributesForElementsInRect=[UICollectionViewLayoutAttri