How do I make a UIScrollView scroll to the top?
15 Answers
UPDATE FOR iOS 7
[self.scrollView setContentOffset:
CGPointMake(0, -self.scrollView.contentInset.top) animated:YES];
ORIGINAL
[self.scrollView setContentOffset:CGPointZero animated:YES];
or if you want to preserve the horizontal scroll position and just reset the vertical position:
[self.scrollView setContentOffset:CGPointMake(self.scrollView.contentOffset.x, 0)
animated:YES];
iOS 11 and above
Try to play around with the new adjustedContentInset
(It should even work with prefersLargeTitles
, safe area
etc.)
For example (scroll to the top):
var offset = CGPoint(
x: -scrollView.contentInset.left,
y: -scrollView.contentInset.top)
if #available(iOS 11.0, *) {
offset = CGPoint(
x: -scrollView.adjustedContentInset.left,
y: -scrollView.adjustedContentInset.top)
}
scrollView.setContentOffset(offset, animated: true)
Swift 3.0.1 version of rob mayoff's answer :
self.scrollView.setContentOffset(
CGPoint(x: 0,y: -self.scrollView.contentInset.top),
animated: true)
I think I have an answer that should be fully compatible with iOS 11 as well as prior versions (for vertical scrolling)
This takes into account the new adjustedContentInset and also accounts for the additional offset required when prefersLargeTitles is enabled on the navigationBar which appears to require an extra 52px offset on top of whatever the default is
This was a little tricky because the adjustedContentInset changes depending on the titleBar state (large title vs small title) so I needed to check and see what the titleBar height was and not apply the 52px offset if its already in the large state. Couldn't find any other method to check the state of the navigationBar so if anyone has a better option than seeing if the height is > 44.0 I'd like to hear it
func scrollToTop(_ scrollView: UIScrollView, animated: Bool = true) {
if #available(iOS 11.0, *) {
let expandedBar = (navigationController?.navigationBar.frame.height ?? 64.0 > 44.0)
let largeTitles = (navigationController?.navigationBar.prefersLargeTitles) ?? false
let offset: CGFloat = (largeTitles && !expandedBar) ? 52: 0
scrollView.setContentOffset(CGPoint(x: 0, y: -(scrollView.adjustedContentInset.top + offset)), animated: animated)
} else {
scrollView.setContentOffset(CGPoint(x: 0, y: -scrollView.contentInset.top), animated: animated)
}
}
Inspired by Jakub's solution
To fully replicate the status bar scrollToTop behavior we not only have to set the contentOffset but also want to make sure the scrollIndicators are displayed. Otherwise the user can quickly get lost.
The only public method to accomplish this is flashScrollIndicators
. Unfortunately, calling it once after setting the contentOffset has no effect because it's reset immediately. I found it works when doing the flash each time in scrollViewDidScroll:
.
// define arbitrary tag number in a global constants or in the .pch file
#define SCROLLVIEW_IS_SCROLLING_TO_TOP_TAG 19291
- (void)scrollContentToTop {
[self.scrollView setContentOffset:CGPointMake(self.scrollView.contentOffset.x, -self.scrollView.contentInset.top) animated:YES];
self.scrollView.tag = SCROLLVIEW_IS_SCROLLING_TO_TOP_TAG;
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.3 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
self.scrollView.tag = 0;
});
}
In your UIScrollViewDelegate (or UITable/UICollectionViewDelegate) implement this:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if (scrollView.tag == SCROLLVIEW_IS_SCROLLING_TO_TOP_TAG) {
[scrollView flashScrollIndicators];
}
}
The hide delay is a bit shorter compared to the status bar scrollToTop behavior but it still looks nice.
Note that I'm abusing the view tag to communicate the "isScrollingToTop" state because I need this across view controllers. If you're using tags for something else you might want to replace this with an iVar or a property.
It's very common when your navigation bar overlaps the small portion of the scrollView content and it looks like content starts not from the top. For fixing it I did 2 things:
- Size Inspector - Scroll View - Content Insets --> Change from Automatic to Never.
- Size Inspector - Constraints- "Align Top to" (Top Alignment Constraints)- Second item --> Change from Superview.Top to Safe Area.Top and the value(constant field) set to 0
Scroll to top for UITableViewController
, UICollectionViewController
or any UIViewController
having UIScrollView
extension UIViewController {
func scrollToTop(animated: Bool) {
if let tv = self as? UITableViewController {
tv.tableView.setContentOffset(CGPoint.zero, animated: animated)
} else if let cv = self as? UICollectionViewController{
cv.collectionView?.setContentOffset(CGPoint.zero, animated: animated)
} else {
for v in view.subviews {
if let sv = v as? UIScrollView {
sv.setContentOffset(CGPoint.zero, animated: animated)
}
}
}
}
}
iOS 2.0+ Mac Catalyst 13.0+
You can try: scrollView.scrollsToTop = true
You can refer it from documentation of developer.apple.com
I tried all the ways. But nothing worked for me. Finally I did like this.
I added self.view .addSubview(self.scroll)
line of code in the viewDidLoad. After started setting up frame for scroll view and added components to scroll view.
It worked for me.
Make sure you added self.view .addSubview(self.scroll)
line in the beginning. then you can add UI elements.