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

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()
}

其他回答

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)

滚动到顶部

- CGPoint topOffset = CGPointMake(0, 0);
- [scrollView setContentOffset:topOffset animated:YES];

滚动到底部

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

确保内容底部可见的一个好方法是使用以下公式:

contentOffsetY = MIN(0, contentHeight - boundsHeight)

这确保内容的下边缘始终位于视图的下边缘或高于视图的下边缘。MIN(0,…)是必需的,因为UITableView(可能还有UIScrollView)确保当用户试图通过可见的抓取contentOffsetY = 0来滚动时,contentOffsetY >= 0。对于用户来说,这看起来很奇怪。

实现这个的代码是:

UIScrollView scrollView = ...;
CGSize contentSize = scrollView.contentSize;
CGSize boundsSize = scrollView.bounds.size;
if (contentSize.height > boundsSize.height)
{
    CGPoint contentOffset = scrollView.contentOffset;
    contentOffset.y = contentSize.height - boundsSize.height;
    [scrollView setContentOffset:contentOffset animated:YES];
}

Xamarin的。iOS版本的接受答案

var bottomOffset = new CGPoint (0,
     scrollView.ContentSize.Height - scrollView.Frame.Size.Height
     + scrollView.ContentInset.Bottom);

scrollView.SetContentOffset (bottomOffset, false);

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];