我怎么能让一个UIScrollView滚动到我的代码底部?或者用更一般的方式,到子视图的任意点?
当前回答
你可以使用UIScrollView的setContentOffset:animated:函数滚动到内容视图的任何部分。这里有一些代码可以滚动到底部,假设你的scrollView是self.scrollView:
objective - c:
CGPoint bottomOffset = CGPointMake(0, self.scrollView.contentSize.height - self.scrollView.bounds.size.height + self.scrollView.contentInset.bottom);
[self.scrollView setContentOffset:bottomOffset animated:YES];
迅速:
let bottomOffset = CGPoint(x: 0, y: scrollView.contentSize.height - scrollView.bounds.height + scrollView.contentInset.bottom)
scrollView.setContentOffset(bottomOffset, animated: true)
其他回答
正如这里所解释的 https://janeshswift.com/ios/swift/how-to-scroll-to-a-position-programmatically-in-uiscrollview/
我们可以创建一个自定义UIScrollView扩展为
extension UIScrollView {
func scrollToTop(animated: Bool = false) {
setContentOffset(CGPoint(x: contentOffset.x, y: -adjustedContentInset.top), animated: animated)
}
var bottomContentOffsetY: CGFloat {
max(contentSize.height - bounds.height + adjustedContentInset.bottom, -adjustedContentInset.top)
}
func scrollToBottom(animated: Bool = false) {
setContentOffset(CGPoint(x: contentOffset.x, y: bottomContentOffsetY), animated: animated)
}
func scrollToLeading(animated: Bool = false) {
setContentOffset(CGPoint(x: -adjustedContentInset.left, y: contentOffset.y), animated: animated)
}
var trailingContentOffsetX: CGFloat {
max(contentSize.width - bounds.width + adjustedContentInset.right, -adjustedContentInset.left)
}
func scrollToTrailing(animated: Bool = false) {
setContentOffset(CGPoint(x: trailingContentOffsetX, y: contentOffset.y), animated: animated)
}
func scrollViewToVisible(_ view: UIView, animated: Bool = false) {
scrollRectToVisible(convert(view.bounds, from: view), animated: true)
}
var isOnTop: Bool {
contentOffset.y <= -adjustedContentInset.top
}
var isOnBottom: Bool {
contentOffset.y >= bottomContentOffsetY
}
}
把它当作——
DispatchQueue.main.async {
self.itemsScrollView.scrollToBottom()
}
Valdyr,希望这对你有帮助
CGPoint bottomOffset = CGPointMake(0, [textView contentSize].height - textView.frame.size.height);
if (bottomOffset.y > 0)
[textView setContentOffset: bottomOffset animated: YES];
看起来这里所有的答案都没有考虑到安全区域。 从iOS 11开始,iPhone X引入了安全区域。这可能会影响scrollView的contentInset。
对于iOS 11及以上版本,正确地滚动到底部,包括插入的内容。你应该使用adjustedContentInset而不是contentInset。检查这段代码:
迅速:
let bottomOffset = CGPoint(x: 0, y: scrollView.contentSize.height - scrollView.bounds.height + scrollView.adjustedContentInset.bottom)
scrollView.setContentOffset(bottomOffset, animated: true)
objective - c
CGPoint bottomOffset = CGPointMake(0, self.scrollView.contentSize.height - self.scrollView.bounds.size.height + self.scrollView.adjustedContentInset.bottom);
[self.scrollView setContentOffset:bottomOffset animated:YES];
Swift扩展(这保留了原来的contenttoffset .x):
extension UIScrollView {
func scrollsToBottom(animated: Bool) {
let bottomOffset = CGPoint(x: contentOffset.x,
y: contentSize.height - bounds.height + adjustedContentInset.bottom)
setContentOffset(bottomOffset, animated: animated)
}
}
引用:
adjustedContentInset
最简单的解决方案:
[scrollview scrollRectToVisible:CGRectMake(scrollview.contentSize.width - 1,scrollview.contentSize.height - 1, 1, 1) animated:YES];
你可以使用UIScrollView的setContentOffset:animated:函数滚动到内容视图的任何部分。这里有一些代码可以滚动到底部,假设你的scrollView是self.scrollView:
objective - c:
CGPoint bottomOffset = CGPointMake(0, self.scrollView.contentSize.height - self.scrollView.bounds.size.height + self.scrollView.contentInset.bottom);
[self.scrollView setContentOffset:bottomOffset animated:YES];
迅速:
let bottomOffset = CGPoint(x: 0, y: scrollView.contentSize.height - scrollView.bounds.height + scrollView.contentInset.bottom)
scrollView.setContentOffset(bottomOffset, animated: true)
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