xcode CollectionView 滚动到顶部
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CollectionView scroll to top
提问by KAR
I have one CollectionViewController and have 10 cells in it.
我有一个 CollectionViewController，里面有 10 个单元格。
But when I run the app it displays the cell at bottom, but I want to display it from top cell at viewDidLoad.
但是当我运行应用程序时，它会在底部显示单元格，但我想在 viewDidLoad 中从顶部单元格显示它。
I tried many things but it didn't work.
我尝试了很多东西，但没有奏效。
How to fix it?
如何解决？
采纳答案by User511
Add this line after reloading the collection view.
重新加载集合视图后添加此行。
[self.collectionView scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionTop animated:NO];
Edit:
编辑：
Just want to add one more point here is if collectionView datasource has ZERO elements or it is nilthen above code will not work and probably crash your app.
只是想在这里再补充一点，如果 collectionView 数据源具有零元素，或者nil上面的代码将不起作用并且可能会导致您的应用程序崩溃。
Write condition to check that datasource is available or not!
编写条件以检查数据源是否可用！
if (self.dataArray.count > 0) {
[self.collectionView scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionTop animated:NO];
}
Where, dataArrayis your datasource.
哪里，dataArray是你的数据源。
回答by Lam Nguyen
in swift 3: after reloadData()
在 swift 3 中：在 reloadData() 之后
self.collectionView.setContentOffset(CGPoint(x:0,y:0), animated: true)
回答by Vinith
Add this piece of code after reloading the collection view:
重新加载集合视图后添加这段代码：
swift
迅速
yourCollectionView.setContentOffset(CGPoint.zero, animated: true)
yourCollectionView.setContentOffset(CGPoint.zero, animated: true)
objective-c
目标-c
[yourCollectionView setContentOffset:CGPointZero animated:YES];
[yourCollectionView setContentOffset:CGPointZero animated:YES];
回答by CSE 1994
Its work fine......
它的工作正常......
collectionView.setContentOffset(.zero, animated: false)
回答by erdikanik
Make animated option false. Maybe some view animations are running during your collection view animation process.
将动画选项设为 false。也许一些视图动画在您的集合视图动画过程中正在运行。
collectionView.scrollToItem(at: indexPath, at: .top, animated: false)
回答by Monika Patel
Please try this one
请试试这个
[self.yourcollectionview scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionTop animated:NO];
回答by JigneshP
To display the data from top cell in collectionView you can use one method
要在 collectionView 中显示来自顶部单元格的数据，您可以使用一种方法
[collectionView setScrollsToTop:YES];
Hope it will Help You.
希望它会帮助你。
