我想你要找的是UIImageView提供的focusedFrameGuide。
使用imageview.focusedFrameGuide.layoutFrame可以确定如何重新定位标签。

使用“自动布局”需要设置两个约束：

focusedConstraint = label.topAnchor.constraint(equalTo: imageView.focusedFrameGuide.bottomAnchor)
unfocusedConstraint = label.topAnchor.constraint(equalTo: imageView.bottomAnchor)

并在didUpdateFocus上激活/停用：

override func didUpdateFocus(in context: UIFocusUpdateContext, with coordinator: UIFocusAnimationCoordinator) {
        super.didUpdateFocus(in: context, with: coordinator)

        if context.nextFocusedView == self {
            unfocusedConstraint?.isActive = false
            focusedConstraint?.isActive = true
        } else if context.previouslyFocusedView == self {
            focusedConstraint?.isActive = false
            unfocusedConstraint?.isActive = true
        }

        coordinator.addCoordinatedAnimations({
            self.layoutIfNeeded()
        }, completion: nil)
    }