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

而马特的解决方案似乎对我来说是正确的,你需要考虑到集合视图嵌入,如果有一个已经设置。

修改后的代码为:

CGSize csz = sv.contentSize;
CGSize bsz = sv.bounds.size;
NSInteger bottomInset = sv.contentInset.bottom;
if (sv.contentOffset.y + bsz.height + bottomInset > csz.height) {
    [sv setContentOffset:CGPointMake(sv.contentOffset.x, 
                                     csz.height - bsz.height + bottomInset) 
                animated:YES];
}

其他回答

只是对已有答案的一个改进。

CGPoint bottomOffset = CGPointMake(0, self.scrollView.contentSize.height - self.scrollView.bounds.size.height + self.scrollView.contentInset.bottom);
[self.scrollView setContentOffset:bottomOffset animated:YES];

它还负责底部的嵌入(以防你在键盘可见时使用它来调整滚动视图)

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)

而马特的解决方案似乎对我来说是正确的,你需要考虑到集合视图嵌入,如果有一个已经设置。

修改后的代码为:

CGSize csz = sv.contentSize;
CGSize bsz = sv.bounds.size;
NSInteger bottomInset = sv.contentInset.bottom;
if (sv.contentOffset.y + bsz.height + bottomInset > csz.height) {
    [sv setContentOffset:CGPointMake(sv.contentOffset.x, 
                                     csz.height - bsz.height + bottomInset) 
                animated:YES];
}

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()
}

使用(可选)footerView和contentInset,解决方案是:

CGPoint bottomOffset = CGPointMake(0, _tableView.contentSize.height - tableView.frame.size.height + _tableView.contentInset.bottom);
if (bottomOffset.y > 0) [_tableView setContentOffset: bottomOffset animated: YES];