iOS - Collection判断滑动方向

(void)scrollViewDidScroll:(UIScrollView *)scrollView {
CGPoint scrollVelocity = [scrollView.panGestureRecognizer translationInView:self.view];
if (scrollVelocity.x > 0) {
// 向左滑
}else {
// 向右滑
}

if (scrollVelocity.y > 0) {
// 向上滑
}else{
// 向下滑
}
}