Scroll UITextView To Bottom

Question

I am making a an app that has a UITextView and a button.

When I click the button some text will add in the UITextView.

But when clicking the button, I wan't to scroll down to the bottom of the text field so the user can see the last text added.

How to make the UITextView to scroll down to the bottom?

I tried:

int numLines = LogTextView.contentSize.height / LogTextView.font.lineHeight+1;
NSLog(@"%d",numLines);

NSUInteger length = self.LogTextView.text.length;
self.LogTextView.selectedRange = NSMakeRange(0, length);

but it will not work...

I also tried:

self.LogTextView.contentSize=CGSizeMake(length,0);

First of all is text view because a UITextView, because the text field doesn't have a scroll. ;) And maybe you could use `scrollRangeToVisible` method :) — danypata, May 22 '13 at 18:02
as @danypata questioned, is this a uitextview, or a uitextfield in a uiscrollview? you referenced both text field and text view in the question. — andrew lattis, May 22 '13 at 18:08
@andrewlattis the question is about `UITextView` which is a sub of `UIScrollView` which has `contentSize` as a property. — Dan Rosenstark, Apr 19 '16 at 19:36

score 84 · Accepted Answer · edited May 19 '18 at 22:47

84

You can use the following code if you are talking about UITextView:

-(void)scrollTextViewToBottom:(UITextView *)textView {
     if(textView.text.length > 0 ) {
        NSRange bottom = NSMakeRange(textView.text.length -1, 1);
        [textView scrollRangeToVisible:bottom];
     }

}

SWIFT 4:

func scrollTextViewToBottom(textView: UITextView) {
    if textView.text.count > 0 {
        let location = textView.text.count - 1
        let bottom = NSMakeRange(location, 1)
        textView.scrollRangeToVisible(bottom)
    }
}

edited May 19 '18 at 22:47

andym

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6

answered May 22 '13 at 18:09

danypata

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2

DON'T FORGET TO ADD [textView setScrollEnabled:NO]; [textView setScrollEnabled:YES]; – Ofir Malachi Aug 13 '17 at 08:43
4

@ofirmalachi, did you mean to write conflicting statements in your comment above? – stuckj May 16 '19 at 13:48
@stuckj I think what he meant what disable scrolling when it is still scrolling down and the enable it again after it is finished. CMIIW. – Bawenang Rukmoko Pardian Putra Sep 09 '22 at 01:20
Note using `scrollRangeToVisible` with large texts may make `UITextView` freeze because of animation. Better use `contentOffset` as shown here https://stackoverflow.com/a/42478029/3004003, but set `animated` to `false` – schmidt9 Oct 31 '22 at 17:38

score 19 · Answer 2 · edited May 23 '17 at 12:17

19

Try this if you have problem on iOS 7 or above. See this SO answer.

- (void)scrollTextViewToBottom:(UITextView *)textView {
    NSRange range = NSMakeRange(textView.text.length, 0);
    [textView scrollRangeToVisible:range];
    // an iOS bug, see https://stackoverflow.com/a/20989956/971070
    [textView setScrollEnabled:NO];
    [textView setScrollEnabled:YES];
}

edited May 23 '17 at 12:17

Community

1
1

answered Oct 18 '15 at 05:09

Hong Duan

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IOS 13 and the bug is still here! – Mohamed Salah Feb 15 '20 at 05:10

score 12 · Answer 3 · answered Feb 27 '17 at 04:51

12

With Swift 3

let bottom = self.textView.contentSize.height - self.textView.bounds.size.height
self.textView.setContentOffset(CGPoint(x: 0, y: bottom), animated: true)

answered Feb 27 '17 at 04:51

zeeawan

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2
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It should work. Where are you using this code? Make sure you're using it after textView has been loaded. – zeeawan Mar 14 '17 at 21:03
It's after viewDidAppear, and textview is fully loaded, with content. Might be related to the fact that the textview's content is larger than the screen's bounds by a large margin – xaphod Mar 14 '17 at 21:04
1

I've just re-verified and it's working just fine. I've created a new single view project, drag and drop a textView with default size and default text, connected outlet, put this code inside viewDidAppear. And it correctly scrolled to bottom. – zeeawan Mar 14 '17 at 21:53
It's better to add check if bottom positive or not, because if it is negative then there is no need to change contentOffset. – Ruslan Mansurov Jul 05 '17 at 09:06
Doesn't work for me (iOS11). My text spans many lines and uses a custom font. – neoneye Feb 27 '18 at 09:53

neoneye · Answer 4 · 2020-07-18T05:17:53.290

7

Swift 5

extension UITextView {
    func simple_scrollToBottom() {
        let textCount: Int = text.count
        guard textCount >= 1 else { return }
        scrollRangeToVisible(NSRange(location: textCount - 1, length: 1))
    }
}

// Usage
textView.simple_scrollToBottom()

edited Jul 18 '20 at 05:17

answered Feb 27 '18 at 10:22

neoneye

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Excellent recommendation! Works really well. Placed the extension at bottom of code after class } and then used the //Usage. code in the button Action. – David_2877 Jul 06 '20 at 12:22
change this for swift 5 scrollRangeToVisible(NSRange(location: textCount - 1, length: 1)) – AMAN77 Jul 16 '20 at 14:20
Thanks @AMAN77 I have inserted your changes. – neoneye Jul 18 '20 at 05:18
It is need to be called by delay after set text – Fa.Shapouri Jul 29 '23 at 14:53

Chris Amelinckx · Answer 5 · 2021-03-17T03:53:12.807

5

Make a range, specifying encoding, to the last character, then scroll to that range Something other than utf8 might be appropriate depending on your content

let range = NSMakeRange(self.textView.text.lengthOfBytes(using: .utf8), 0);
self.textView.scrollRangeToVisible(range);

edited Mar 17 '21 at 03:53

answered Jun 21 '17 at 02:28

Chris Amelinckx

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The best solution of all with the minimum lag! – Daniele Ceglia Jul 27 '18 at 08:56
this works on iOS 14.4 as well. smooth and no issues at all – Radu Ursache Mar 09 '21 at 09:07

score 4 · Answer 6 · edited Jan 17 '18 at 01:46

You have to implement a delegate method. The code below checks whether a newline has been entered and, if so, scrolls to the bottom of the textView:

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{

    if ([text isEqualToString:@"\n"]) {
        textView.contentOffset = CGPointMake(0.0, textView.contentSize.height);
    }
    return YES;
}

score 3 · Answer 7 · edited Aug 11 '14 at 17:15

3

This works for me! :D

CGPoint bottomOffset = CGPointMake(0, self.textView.contentSize.height - self.textView.bounds.size.height);
[self.description1 setContentOffset:bottomOffset animated:YES];

edited Aug 11 '14 at 17:15

Kevin Chen

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answered Jan 19 '14 at 19:50

Brandon Boynton

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1
9

This works well for when you need to do this without animation (with animated:NO of course). Note that you might want to add in a `max(0, ...` to scroll down only when necessary. – David Lawson Oct 13 '16 at 08:44

score 3 · Answer 8 · edited Feb 13 '20 at 19:23

As a generic approach for scrolling to bottom, it can be done on a UIScrollView.

extension UIScrollView {
    func scrollToBottom() {
        let contentHeight = contentSize.height - frame.size.height
        let contentoffsetY = max(contentHeight, 0)
        setContentOffset(CGPoint(x: 0, y: contentoffsetY), animated: true)
    }
}

This will work on all descendants of UIScrollView like UITextView, UITableView etc..

Nathan Hosselton · Answer 9 · 2020-03-12T18:15:54.983

3

textView.scrollRangeToVisible(NSRange(..<textView.text.endIndex, in: textView.text))

This solution does a couple of notable things slightly different:

Utilizes the String.Index interface (likely more performant than e.g. .count)
Uses a PartialRangeUpTo which avoids an explicit range start position, reducing the code to a clean one-liner

edited Mar 12 '20 at 18:15

answered Jan 10 '20 at 20:28

Nathan Hosselton

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score 1 · Answer 10 · answered Sep 19 '19 at 14:01

The Swift version of @Hong Duan answer

func scrollTextViewToBottom(textView: UITextView) {
    if textView.text.count > 0 {
        let location = textView.text.count - 1
        let bottom = NSMakeRange(location, 1)
        textView.scrollRangeToVisible(bottom)

        // an iOS bug, see https://stackoverflow.com/a/20989956/971070
        textView.isScrollEnabled = false
        textView.isScrollEnabled = true
    }
}

Scroll UITextView To Bottom

10 Answers10

Swift 5

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