上下滚动时增加或减小imageView的高度
extension DetailViewController: UIScrollViewDelegate {
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if (self.lastContentOffset > scrollView.contentOffset.y) {
UIView.animate(withDuration: 0.2, animations: {
print("going down")
if self.imgViewHeight.constant >= 200 {
self.blurView.alpha = 0
self.backButton.isHidden = false
}
else if self.imgViewHeight.constant <= 200{
self.blurView.alpha = 1
self.imgViewHeight.constant = self.imgViewHeight.constant + 4
}
}, completion: nil)
}
else if (self.lastContentOffset < scrollView.contentOffset.y) {
UIView.animate(withDuration: 0.2, animations: {
if self.imgViewHeight.constant <= 72 {
self.blurView.alpha = 1
self.backButton.isHidden = false
self.descriptions.isScrollEnabled = true
}
else if self.imgViewHeight.constant >= 72{
self.blurView.alpha = 1
self.imgViewHeight.constant = self.imgViewHeight.constant - 4
}
print("lolol:\(self.imgViewHeight.constant)")
}, completion: nil)
}
else {
}
self.lastContentOffset = scrollView.contentOffset.y
}
}
最佳答案
您可以使用ScrollView函数，例如：
func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
//your code when you want start scrolling
}
func scrollViewWillEndDragging(_ scrollView: UIScrollView) {
//your code when you want run after stop scrolling
}
关于swift - 上下滚动时增加或减少imageView的高度，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/56287511/