UICollectionView didSelectItemAt 不起作用

Question

点击集合视图单元格时我需要动画。我为它编写了一个覆盖函数。但是当我在自定义单元格上覆盖

UICollectionView didSelectItemAt

时，

touchesBegan

不起作用。

视图控制器

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
    self.answersCollectionView.selectItem(at: indexPath, animated: true, scrollPosition: .centeredHorizontally)
    self.selectedIndex = indexPath.item
}

自定义单元格类

public override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    UIView.animate(withDuration: 0.5) {
        self.transform = CGAffineTransform(scaleX: 0.9, y: 0.9)
    }
}

public override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
    UIView.animate(withDuration: 0.1) {
        self.transform = CGAffineTransform(scaleX: 1, y: 1)
    }
}

public override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    UIView.animate(withDuration: 0.1) {
        self.transform = CGAffineTransform(scaleX: 1, y: 1)
    }
}

我想为选择设置动画。

Answer 1

您写道“当点击集合视图单元格时我需要动画......”。如果这是您唯一的要求，我会这样做：

1. 确保您的集合视图允许选择，如下所示：

   myCollectionView.allowsSelection = true

2. 向您的 CustomCell 添加一个函数，如下所示：

    class CustomCellClass: UICollectionViewCell {
    //configure the cell as you normally would
   
        /// animates cell after a selection
        func animateSelection() {
            //please note that this is the most basic way of animating
            //there are multiple other ways. check out the provided link below in the post
            UIView.animate(withDuration: 0.5) { 
                self.transform = CGAffineTransform(scaleX: 0.9, y: 0.9)
            } completion: { _ in
                UIView.animate(withDuration: 0.1) { 
                    self.transform = CGAffineTransform(scaleX: 1, y: 1)
                }
            }
        }
    }
   

3. 在

   didSelectItemAt

   回调期间调用这个新函数。

    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        //you don't need to do this - the cell is already selected
        //self.answersCollectionView.selectItem(at: indexPath, animated: true, scrollPosition: .centeredHorizontally)
   
        if let selectedCell = collectionView.cellForItem(at: indexPath) as? CustomCellClass {
            selectedCell.animateSelection()
        }
   
        //do other things you need to do in order to react to cell selection
        ..
    }
   

这里是交流，大家可以参考看看其他动画技巧