Ios 获取CollectionViewContentSize

Ios 获取CollectionViewContentSize,ios,objective-c,swift,Ios,Objective C,Swift,我正试图像苹果的Photo objective C实现一样获得CollectionViewContentSize。下面是代码 苹果的代码 CGSize cellSize = ((UICollectionViewFlowLayout *)self.collectionViewLayout).itemSize; 我的代码 let cellSize: CGSize = UICollectionViewFlowLayout.collectionViewContentSize(self.collec

我正试图像苹果的Photo objective C实现一样获得
CollectionViewContentSize
。下面是代码

苹果的代码

 CGSize cellSize = ((UICollectionViewFlowLayout *)self.collectionViewLayout).itemSize;
我的代码

 let cellSize: CGSize = UICollectionViewFlowLayout.collectionViewContentSize(self.collectionViewLayout)
我得到一个错误,说
(UICollectionViewLayout)->'不能转换为'UICollectionViewFlowLayout->()->CGSize'

ObjC

  CGSize cellSize = ((UICollectionViewFlowLayout *)self.collectionViewLayout).itemSize;
迅捷的

这很简单: self.collectionViewLayout返回
UICollectionViewLayout
键入not
UICollectionViewFlowLayout
,因此您应该强制转换它:

if let layout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout {
    let cellSize: CGSize = UICollectionViewFlowLayout.collectionViewContentSize(layout)()
}

您是否尝试过
collectionView.contentSize
if let layout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout {
    let cellSize: CGSize = UICollectionViewFlowLayout.collectionViewContentSize(layout)()
}