ios - 点击扩展 UICollectionViewCell

Question

我有垂直向上滚动的 UICollectionView，我想在点击时更改项目高度。在默认状态下，单元格的高度为屏幕高度的 2/3。我试过以下:

override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        let cell = collectionView.cellForItem(at: indexPath)
            if let cell = cell as? TutorialCell {
                let attribute = layout.layoutAttributesForItem(at: indexPath)
                attribute?.frame = CGRect.init(x: 0, y: 0, width: UIScreen.main.bounds.size.width,
                                               height: UIScreen.main.bounds.size.height)
                collectionView.reloadItems(at: [indexPath])

            }
        print(indexPath.row)
    }

但它不起作用。

Answer 1

您可以通过 UICollectionViewDelegateFlowLayout 方法 sizeForItemAt 实现此目的

声明一个变量

var selectIndex: Int = -1

在你的didSelectItemAt中添加这个

override func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    self.selectIndex = indexPath.row

    collectionView.reloadData()
}

为 UICollectionViewDelegateFlowLayout 添加扩展

extension YourViewController: UICollectionViewDelegateFlowLayout {

    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {

        let height = (self.selectIndex == indexPath.row ) ?
            UIScreen.main.bounds.size.height :
            (UIScreen.main.bounds.size.height * 2) / 3

        return CGSize(width:UIScreen.main.bounds.size.width, height:height)
    }
}