UICollectionView 动画数据更改 [英] UICollectionView animate data change

问题描述

在我的项目中，我使用 UICollectionView 来显示图标网格.

In my Project I use UICollectionView to display a grid of icons.

用户可以通过单击一个分段控件来更改排序，该控件调用具有不同 NSSortDescriptor 的核心数据的提取.

The user is able to change the ordering by clicking a segmented control which calling a fetch from core data with different NSSortDescriptor.

数据量始终相同，只是在不同的部分/行中结束:

- (IBAction)sortSegmentedControlChanged:(id)sender {

   _fetchedResultsController = nil;
   _fetchedResultsController = [self newFetchResultsControllerForSort];

   NSError *error;
   if (![self.fetchedResultsController performFetch:&error]) {
       NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
   }

   [self.collectionView reloadData];
}

问题是 reloadData 不会为更改设置动画，UICollectionView 只是弹出新数据.

The problem is that reloadData doesn't animate the change, UICollectionView just pops with the new data.

我应该跟踪一个单元格在更改之前和之后的 indexPath 中，并使用 [self.collectionView moveItemAtIndexPath: toIndexPath:] 来执行更改的动画还是有更好的方法?

Should I keep track in which indexPath a cell was before and after change, and use [self.collectionView moveItemAtIndexPath: toIndexPath:] to perform the animation for the change or there is a better method ?

我对子类化 collectionViews 没有太多了解，所以任何帮助都会很棒......

I didn't get much into subclassing collectionViews so any help will be great...

谢谢，比尔.

推荐答案

reloadData 不设置动画，在放入 UIView 动画块时也不可靠.它想在 UICollecitonView performBatchUpdates 块中，所以尝试更像:

reloadData doesn't animate, nor does it reliabably do so when put in a UIView animation block. It wants to be in a UICollecitonView performBatchUpdates block, so try something more like:

[self.collectionView performBatchUpdates:^{
    [self.collectionView reloadSections:[NSIndexSet indexSetWithIndex:0]];
} completion:^(BOOL finished) {
    // do something on completion 
}];

这篇关于UICollectionView 动画数据更改的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！