Swift：UICollectionView Cell在实现sizeForItemAtIndexPath时无法更新帧

Question

当我实现以下代码时：

dynamic var predicate: NSPredicate? = {
    return NSPredicate { object, _ in
        (object as? MyClass)?.result
    }
}()

通过使用sizeForItemAt方法，我可以绘制我想要的帧，但是我的自定义collectionview单元格无法更新，我错过了哪里，请帮助我!!

my custom cell

debug view

Answer 1

i fix it by this ref UICollectionView cell subviews do not resize

thanks guys , at frist still have problem with my Cell.imageview , can not shape-round as i want , and i create a class for imageview ,below:

class CellImageView: UIImageView {
override func layoutSubviews() {
    super.layoutSubviews()
    let radius: CGFloat = self.bounds.size.width / 2.0
    self.layer.cornerRadius = radius
    self.clipsToBounds = true

}

and anything work perfectly

Answer 2

在iOS 13中，对于我来说，我先将estimatedItemSize固定为.zero，然后将itemSize设置为；

if let layout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout {
 layout.estimatedItemSize = .zero
 layout.itemSize = CGSize(width: collectionView.frame.size.width, height: 80)
}