UICollectionView.scrollToItem设置动画速度

collectionView.layoutIfNeeded() // 确保布局已更新

let indexPath = IndexPath(item: desiredIndex, section: desiredSection)
let attributes = collectionView.layoutAttributesForItem(at: indexPath)

let contentOffset = CGPoint(x: attributes.frame.origin.x - collectionView.contentInset.left, y: attributes.frame.origin.y - collectionView.contentInset.top)

UIView.animate(withDuration: 0.5, delay: 0, options: .curveEaseInOut, animations: {
    self.collectionView.setContentOffset(contentOffset, animated: false)
}, completion: nil)