3D效果

-(NSArray *)layoutAttributesForElementsInRect:(CGRect)rect{    NSArray *array = [super layoutAttributesForElementsInRect:rect];    CGRect visibleRect;    visibleRect.origin = self.collectionView.contentOffset;    visibleRect.size = self.collectionView.bounds.size;    for (UICollectionViewLayoutAttributes* attributes in array) {        CGFloat distance = CGRectGetMidX(visibleRect) - attributes.center.x;        NSLog(@"%f",distance);        CGFloat normalizedDistance = distance / ActiveDistance;        CGFloat zoom = 1 + ScaleFactor*(1 - ABS(normalizedDistance));        //3D效果        attributes.transform3D = CATransform3DMakeScale(1.0, zoom, 1.0);        attributes.zIndex = 1;    }    return array;}复制代码

分页

pagingEnabled = true //可根据页面宽度进行分页复制代码

特殊情况下需要根据代理方法去计算分页的距离

- (CGPoint)targetContentOffsetForProposedContentOffset:(CGPoint)offset                                 withScrollingVelocity:(CGPoint)velocity复制代码

- (CGPoint)targetContentOffsetForProposedContentOffset:(CGPoint)offset                                 withScrollingVelocity:(CGPoint)velocity {        CGRect cvBounds = self.collectionView.bounds;    CGFloat halfWidth = cvBounds.size.width * 0.5f;    CGFloat proposedContentOffsetCenterX = offset.x + halfWidth;        NSArray* attributesArray = [self layoutAttributesForElementsInRect:cvBounds];        UICollectionViewLayoutAttributes* candidateAttributes;    for (UICollectionViewLayoutAttributes* attributes in attributesArray) {                // == Skip comparison with non-cell items (headers and footers) == //        if (attributes.representedElementCategory !=            UICollectionElementCategoryCell) {            continue;        }                // == First time in the loop == //        if(!candidateAttributes) {            candidateAttributes = attributes;            continue;        }                if (fabs(attributes.center.x - proposedContentOffsetCenterX) <            fabs(candidateAttributes.center.x - proposedContentOffsetCenterX)) {            candidateAttributes = attributes;        }    }        return CGPointMake(candidateAttributes.center.x - halfWidth, offset.y);    }复制代码

引用