快速执行:

extension UIScrollView {
   func scrollToBottom(animated: Bool) {
     if self.contentSize.height < self.bounds.size.height { return }
     let bottomOffset = CGPoint(x: 0, y: self.contentSize.height - self.bounds.size.height)
     self.setContentOffset(bottomOffset, animated: animated)
  }
}

使用它:

yourScrollview.scrollToBottom(animated: true)

Swift版本的易于复制粘贴的接受答案:

let bottomOffset = CGPoint(x: 0, y: scrollView.contentSize.height - scrollView.bounds.size.height)
scrollView.setContentOffset(bottomOffset, animated: true)

如果你以某种方式改变scrollView contentSize(例如，添加一些东西到stackView是在scrollView)，你必须调用scrollView. layoutifneeded()在滚动之前，否则它什么都不做。

例子:

scrollView.layoutIfNeeded()
let bottomOffset = CGPoint(x: 0, y: scrollView.contentSize.height - scrollView.bounds.size.height + scrollView.contentInset.bottom)
if(bottomOffset.y > 0) {
    scrollView.setContentOffset(bottomOffset, animated: true)
}

我发现contentSize并没有真正反映文本的实际大小，所以当尝试滚动到底部时，它会有点偏离。确定实际内容大小的最佳方法实际上是使用NSLayoutManager的usedRectForTextContainer:方法:

UITextView *textView;
CGSize textSize = [textView.layoutManager usedRectForTextContainer:textView.textContainer].size;

要确定在UITextView中实际显示了多少文本，可以通过从帧高度中减去文本容器嵌入来计算。

UITextView *textView;
UIEdgeInsets textInsets = textView.textContainerInset;
CGFloat textViewHeight = textView.frame.size.height - textInsets.top - textInsets.bottom;

然后就很容易滚动了:

// if you want scroll animation, use contentOffset
UITextView *textView;
textView.contentOffset = CGPointMake(textView.contentOffset.x, textSize - textViewHeight);

// if you don't want scroll animation
CGRect scrollBounds = textView.bounds;
scrollBounds.origin = CGPointMake(textView.contentOffset.x, textSize - textViewHeight);
textView.bounds = scrollBounds;

一些数字用于参考空UITextView的不同大小。

textView.frame.size = (width=246, height=50)
textSize = (width=10, height=16.701999999999998)
textView.contentSize = (width=246, height=33)
textView.textContainerInset = (top=8, left=0, bottom=8, right=0)

扩展UIScrollView添加一个scrollToBottom方法:

extension UIScrollView {
    func scrollToBottom(animated:Bool) {
        let offset = self.contentSize.height - self.visibleSize.height
        if offset > self.contentOffset.y {
            self.setContentOffset(CGPoint(x: 0, y: offset), animated: animated)
        }
    }
}

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()
}