CODEWITHSUNDEEP
iosobjective-ciphoneuiscrollviewuikit
Jack Humphries
Jack Humphries

Reputation: 13267

Get UIScrollView to scroll to the top

How do I make a UIScrollView scroll to the top?

Upvotes: 190

Views: 143574

Answers (17)

slushy
slushy

Reputation: 12385

iOS 16

For table and collection views, the following always works for me:

let top = CGRect(x: 0, y: 0, width: 1, height: 1)
tableView.scrollRectToVisible(top, animated: true)
collectionView.scrollRectToVisible(top, animated: true)

For scroll views:

let top = CGPoint(x: 0, y: -adjustedContentInset.top)
scrollView.setContentOffset(top, animated: animated)

adjustedContentInset returns the insets applied by the safe area (if any) and any custom insets applied after instantiation. If either safe or custom insets are applied, the content inset of the scroll view when it's at its top will be negative, not zero, which is why this property should be used.

Upvotes: 2

pkamb
pkamb

Reputation: 34983

In modern iOS, set the the scroll view's content offset back to its top left adjustedContentInset:

let point = CGPoint(x: -scrollView.adjustedContentInset.left,
                    y: -scrollView.adjustedContentInset.top)
    
scrollView.setContentOffset(point, animated: true)

Upvotes: 2

Robocon
Robocon

Reputation: 17

iOS 2.0+ Mac Catalyst 13.0+

You can try: scrollView.scrollsToTop = true

You can refer it from documentation of developer.apple.com

Upvotes: -3

Jakub Truhlář
Jakub Truhlář

Reputation: 20710

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)

Upvotes: 54

Abdul Karim Khan
Abdul Karim Khan

Reputation: 4935

In SWIFT 5 Just set content Offset to zero

scrollView.setContentOffset(CGPoint.zero, animated: true)

Upvotes: 8

Rajasekhar Pasupuleti
Rajasekhar Pasupuleti

Reputation: 1658

For Swift 4

scrollView.setContentOffset(.zero, animated: true)

Upvotes: 66

Vitya Shurapov
Vitya Shurapov

Reputation: 2308

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

Content insets - Never Align ScrolView.Top to Safe Area.Top

Upvotes: 3

user2898617
user2898617

Reputation: 617

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

Upvotes: 3

Andrew Schreiber
Andrew Schreiber

Reputation: 14890

Here is a Swift extension that makes it easy:

extension UIScrollView {
    func scrollToTop() {
        let desiredOffset = CGPoint(x: 0, y: -contentInset.top)
        setContentOffset(desiredOffset, animated: true)
   }
}

Usage:

myScrollView.scrollToTop()

Upvotes: 76

worthbak
worthbak

Reputation: 355

Answer for Swift 2.0/3.0/4.0 and iOS 7+:

let desiredOffset = CGPoint(x: 0, y: -self.scrollView.contentInset.top)
self.scrollView.setContentOffset(desiredOffset, animated: true)

Upvotes: 19

hoak
hoak

Reputation: 125

In iOS7 I had trouble getting a particular scrollview to go to the top, which worked in iOS6, and used this to set the scrollview to go to the top. 

[self.myScroller scrollRectToVisible:CGRectMake(0, 0, 1, 1) animated:NO];

Upvotes: 8

Shoaib
Shoaib

Reputation: 1323

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)
            }
        }
    }
  }
}

Upvotes: 0

RawKnee
RawKnee

Reputation: 323

Swift 3.0.1 version of rob mayoff's answer :

self.scrollView.setContentOffset(
CGPoint(x: 0,y: -self.scrollView.contentInset.top),
animated: true)

Upvotes: 4

Narasimha Nallamsetty
Narasimha Nallamsetty

Reputation: 1263

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.

Upvotes: -3

rob mayoff
rob mayoff

Reputation: 385500

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];

Upvotes: 331

Ortwin Gentz
Ortwin Gentz

Reputation: 54121

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.

Upvotes: 2

Bryan Chen
Bryan Chen

Reputation: 46578

Use setContentOffset:animated:

[scrollView setContentOffset:CGPointZero animated:YES];

Upvotes: 23

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