ios - 如何获取 UICollectionViewCell 的矩形？

Question

UITableView有方法rectForRowAtIndexPath:，但这在UICollectionView中不存在。我正在寻找一种干净的方式来获取单元格的边界矩形，也许我可以将其添加为UICollectionView.

Answer 1

我发现这样做的最佳方法如下：

Objective-C

UICollectionViewLayoutAttributes *attributes = [self.collectionView layoutAttributesForItemAtIndexPath:indexPath];

迅速

let attributes = collectionView.layoutAttributesForItem(at: indexPath)

然后您可以通过attributes.frame或访问该位置attributes.center

Answer 2

只需两行代码即可获得完美的框架：

Objective-C

UICollectionViewLayoutAttributes * theAttributes = [collectionView layoutAttributesForItemAtIndexPath:indexPath];

CGRect cellFrameInSuperview = [collectionView convertRect:theAttributes.frame toView:[collectionView superview]];

斯威夫特 4.2

let theAttributes = collectionView.layoutAttributesForItem(at: indexPath)
let cellFrameInSuperview = collectionView.convert(theAttributes.frame, to: collectionView.superview)

Answer 3

在迅速 3

 let theAttributes:UICollectionViewLayoutAttributes! = collectionView.layoutAttributesForItem(at: indexPath)
 let cellFrameInSuperview:CGRect!  = collectionView.convert(theAttributes.frame, to: collectionView.superview)

Answer 4

迅速你可以这样做：

//for any cell in collectionView
let rect = self.collectionViewLayout.layoutAttributesForItemAtIndexPath(clIndexPath).frame

//if you only need for visible cells
let rect = cellForItemAtIndexPath(indexPath)?.frame

Answer 5

怎么样

-(CGRect)rectForCellatIndexPath:(NSIndexPath *)indexPath {

    UICollectionViewCell *cell = [self cellForItemAtIndexPath:indexPath];

    if (!cell) {
        return CGRectZero;
    }

    return cell.frame;

}

作为一个类别UICollectionView？

#import <UIKit/UIKit.h>

@interface UICollectionView (CellFrame)

-(CGRect)rectForCellatIndexPath:(NSIndexPath *)indexPath;

@end


#import "UICollectionView+CellFrame.h"

@implementation UICollectionView (CellFrame)

-(CGRect)rectForCellatIndexPath:(NSIndexPath *)indexPath {

    UICollectionViewCell *cell = [self cellForItemAtIndexPath:indexPath];

    if (!cell) {
        return CGRectZero;
    }

    return cell.frame;

}

@end