ios 如何从代码中选择 UICollectionView 的项目/单元格
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How to select item/cell of UICollectionView from code
提问by Nikola Kirev
I have implemented a UICollectionViewin my app. My problem is that I need to select (like if the user tapped on it) a cell programmatically.
The method:
我已经UICollectionView在我的应用程序中实现了。我的问题是我需要选择（就像用户点击它一样）一个 cell programmatically。方法：
- (void)selectItemAtIndexPath:(NSIndexPath *)indexPath
animated:(BOOL)animated
scrollPosition:(UICollectionViewScrollPosition)scrollPosition
That is part of the UICollectionViewclass is not what i need to call, since this method does not call:
那是UICollectionView类的一部分不是我需要调用的，因为此方法不调用：
- (void)collectionView:(UICollectionView *)collectionView
didSelectItemAtIndexPath:(NSIndexPath *)indexPath
It just sets the selectedproperty of the cell to YES;
它只是将selected单元格的属性设置为YES;
回答by leviathan
回答by Shirish Kumar
I am calling [self collectionView:yourView didSelectItemAtIndexPath:yourIndexPath]to programmatically select a cell. But in the method cell is always nil. This works perfectly well when user selects a cell.
我正在调用[self collectionView:yourView didSelectItemAtIndexPath:yourIndexPath]以编程方式选择一个单元格。但是在方法中，单元格始终为零。当用户选择一个单元格时，这非常有效。
回答by nopopon
First, you need to make the target cell visible, otherwise [yourCollectionView cellForItemAtIndexPath:yourIndexPath]always returns nil.
首先，您需要使目标单元格可见，否则[yourCollectionView cellForItemAtIndexPath:yourIndexPath]始终返回 nil。
// scroll to the cell
[yourCollectionView scrollToItemAtIndexPath:yourIndexPath
atScrollPosition:UICollectionViewScrollPositionBottom
animated:NO];
// call delegate method
[self collectionView:yourCollectionView didSelectItemAtIndexPath:yourIndexPath];
// now you have selected the cell and can do anything to it in the delegate method :-)
