ios - 长按并拖动时放大 UICollectionViewCell

Question

我想在长按和拖动时缩放 Collection View ，并且当用户结束拖动时，单元格应该采用常规大小。

我正在使用以下步骤创建演示，该演示工作正常，但放大功能未按我的预期工作。 Collection View Example

这是我使用的手势代码:

func handleLongGesture(gesture: UILongPressGestureRecognizer) {

    switch(gesture.state) {

    case UIGestureRecognizerState.Began:
        guard let selectedIndexPath = self.collectionView.indexPathForItemAtPoint(gesture.locationInView(self.collectionView)) else {
            break
        }
        collectionView.beginInteractiveMovementForItemAtIndexPath(selectedIndexPath)
    case UIGestureRecognizerState.Changed:
        collectionView.updateInteractiveMovementTargetPosition(gesture.locationInView(gesture.view!))
    case UIGestureRecognizerState.Ended:
        collectionView.endInteractiveMovement()
    default:
        collectionView.cancelInteractiveMovement()
    }
}

Answer 1

在 Collection View 布局子类上尝试一下:

- (UICollectionViewLayoutAttributes*) layoutAttributesForInteractivelyMovingItemAtIndexPath:(NSIndexPath *)indexPath withTargetPosition:(CGPoint)position
{
    UICollectionViewLayoutAttributes *attributes = [super layoutAttributesForInteractivelyMovingItemAtIndexPath:indexPath withTargetPosition:position];
    attributes.zIndex = NSIntegerMax;
    attributes.transform3D = CATransform3DScale(attributes.transform3D, 1.2f, 1.2f, 1.0);
    return attributes;
}