UICollectionview scrollToItemAtIndexPath，在完成动画之前不加载可见单元格 [英] UICollectionview scrollToItemAtIndexPath, not loading visible cells until animation complete

问题描述

我有一个带有142个单元格的 UICollectionView 。 7.5随时可见。

I have a UICollectionView with 142 Cells. 7.5 are visible at any one time.

我将一个单元格从 indexPath 0移到100。 b $ b但是我也想滚动到那个新位置。

I'm moving a cell from indexPath 0 to say 100. But I also want to scroll to that new position.

下面的代码可以正常工作。但是，它会为移动和滚动设置动画效果，但随后将这些单元加载到中央/移动单元的前面和后面。
我认为是因为单元可重复使用。但是使用142，我无法全部预加载

The code below works fine. But it animates the move and scroll, but then loads the cells in front of and behind the central/moved cell afterwards. I think its because the cells are reusable. but with 142, I can't pre-load all of them

效果不是最好的，我想预加载新位置周围的单元格，4 indexPath 100之前和之后的4，然后查看移动和滚动的动画。您能帮忙吗？

Its not the nicest effect, I would like to pre-load the cells surrounding the new position, 4 before and 4 after indexPath 100, and then see the animation of the move and scroll. can you help please?

UIView.animateWithDuration(animationSpeed, animations: {() -> Void in
    self.collectionView.layoutIfNeeded()
    self.collectionView.scrollToItemAtIndexPath(NSIndexPath(forItem:self.indexPathSelected.row, 
                                                 inSection:0), 
                                                 atScrollPosition: .CenteredHorizontally, 
                                                 animated: true)

})

推荐答案

我找到的唯一答案是在动画中添加几秒钟。这样，在滚动到达时加载单元格

The only answer I have found, is to add a few seconds to the animation. That way the cells are loaded when the scroll arrives

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