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

如果你不需要动画,这是可行的:

[self.scrollView setContentOffset:CGPointMake(0, CGFLOAT_MAX) animated:NO];

其他回答

类别来拯救!

将此添加到共享实用程序头的某处:

@interface UIScrollView (ScrollToBottom)
- (void)scrollToBottomAnimated:(BOOL)animated;
@end

然后是那个实用程序实现:

@implementation UIScrollView(ScrollToBottom)
- (void)scrollToBottomAnimated:(BOOL)animated
{
     CGPoint bottomOffset = CGPointMake(0, self.contentSize.height - self.bounds.size.height);
     [self setContentOffset:bottomOffset animated:animated];
}
@end

然后在任何你喜欢的地方执行它,例如:

[[myWebView scrollView] scrollToBottomAnimated:YES];

Swift 2.2解决方案,考虑了contentInset

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

这应该是一个扩展

extension UIScrollView {

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

注意,您可能想检查bottomOffset。滚动前的Y > 0

Xamarin的。iOS版本的UICollectionView的接受答案,便于复制和粘贴

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

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

CGFloat yOffset = scrollView.contentOffset.y;

CGFloat height = scrollView.frame.size.height;

CGFloat contentHeight = scrollView.contentSize.height;

CGFloat distance = (contentHeight  - height) - yOffset;

if(distance < 0)
{
    return ;
}

CGPoint offset = scrollView.contentOffset;

offset.y += distance;

[scrollView setContentOffset:offset animated:YES];