collectionview实现无限轮播

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
//根据偏移量  计算出index  处于中间范围不操作  其他情况滑动到第一组
int index =  scrollView.contentOffset.x / [UIScreen mainScreen].bounds.size.width;
        if(index >= 1*self.imagesArray.count && index < 2*self.imagesArray.count)
{
return;
}

int item = index % self.imagesArray.count;
NSIndexPath *indexpath = [NSIndexPath indexPathForItem:item inSection:1];
[self.collectionView scrollToItemAtIndexPath:indexpath atScrollPosition:0 animated:NO];

}