ios - 如何在按下按钮时在 Collection View 中滚动(水平)？

Question

我有一个带有图像的 Collection View 。我想在按下按钮时执行滚动。我在谷歌上搜索过我发现只能设置 contentoffset 但我想滚动动画(如果内容超过滚动区域，滚动应该弹跳)。我添加了一个 image为了向您展示我必须做什么，图片中有一个 Collection View ，两侧的小箭头是按钮。

 @IBAction func moveScrollLeft(sender: UIButton) {
    UIView.animateWithDuration(0.2, delay: 0, options: UIViewAnimationOptions.CurveEaseOut, animations: {
        self.imageCollectionView.contentOffset.x -= 50
        }, completion: nil)
    print(imageCollectionView.contentOffset.x)
}

@IBAction func moveScrollRight(sender: UIButton) {
    UIView.animateWithDuration(0.2, delay: 0, options: UIViewAnimationOptions.CurveEaseOut, animations: {
        self.imageCollectionView.contentOffset.x += 50
        }, completion: nil)
    print(imageCollectionView.contentOffset.x)

}

Answer 1

使用 UICollectionview 的 scrollToItemAtIndexPath(_:atScrollPosition:animated:) https://developer.apple.com/library/ios/documentation/UIKit/Reference/UICollectionView_class/#//apple_ref/occ/instm/UICollectionView/scrollToItemAtIndexPath:atScrollPosition:animated :

例如:

let indexPath = NSIndexPath(forRow: 3, inSection: 0)
imageCollectionView.scrollToItemAtIndexPath(indexPath, atScrollPosition: .CenteredHorizontally, animated: true)