objective-c 带有动画的 UICollectionView reloadSections
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原文地址: http://stackoverflow.com/questions/19273447/
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UICollectionView reloadSections with animation
提问by Sergey
I'd like to reload UICollectionView with some interesting animation. In UITableView there's a method called reloadSections:withRowAnimation.
But in UICollectionView there's just reloadSections.
我想用一些有趣的动画重新加载 UICollectionView。在 UITableView 中有一个方法叫做reloadSections:withRowAnimation. 但是在 UICollectionView 中只有reloadSections.
How can I customize reloadSections animation? I definitely saw this in apps on the App Store.
如何自定义 reloadSections 动画？我肯定在 App Store 上的应用程序中看到了这一点。
回答by Fab1n
Just do it like that:
就这样做：
[self.collectionView performBatchUpdates:^{
[self.collectionView reloadSections:[NSIndexSet indexSetWithIndex:0]];
} completion:nil];
回答by Mark Bridges
Swift 3 version:
斯威夫特 3 版本：
collectionView.performBatchUpdates({
let indexSet = IndexSet(integer: 0)
self.collectionView.reloadSections(indexSet)
}, completion: nil)
回答by cldrr
This article here is worth a read: http://victorlin.me/posts/2016/04/29/uicollectionview-invalid-number-of-items-crash-issue
这里的这篇文章值得一读：http: //victorlin.me/posts/2016/04/29/uicollectionview-invalid-number-of-items-crash-issue
TLDR:
域名注册地址：
So it turned out performBatchUpdates calls collectionView(:numberOfItemsInSection:) first before call the given closure to know the item numbers. Next, it calls the closure, and eventually, it calls collectionView(:numberOfItemsInSection:) again to check the number. And here is where the assertion exception thrown.
所以结果是 performBatchUpdates在调用给定的闭包之前先调用 collectionView( :numberOfItemsInSection:) 以了解项目编号。接下来，它调用闭包，并最终再次调用 collectionView(:numberOfItemsInSection:) 来检查数字。这是抛出断言异常的地方。
