Automatic scrolling scrollview

Question

I have a question. I want to display the user some content in a UIScrollView. I want to autoscroll the UIScrollView fast from bottom to top (like in the apple stores iPad). I tried to use DDAutoscrollview (If someone knows), but it doesn't work for me. Do have someone a solution for me to autoscroll a UIScrollView? Any code snippets would be nice.

.h

@interface Interface1 : UIViewController {

    IBOutlet UIScrollView *scroller;
    IBOutlet UILabel *warnung;

}

@property (nonatomic, retain) IBOutlet UIScrollView* scrollView;

.m

- (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    CGPoint bottomOffset = CGPointMake(self.scrollView.contentOffset.x, 
                                       self.scrollView.contentSize.height - 
                                         self.scrollView.bounds.size.height);
    [self.scrollView setContentOffset:bottomOffset animated:NO];

    CGPoint newOffset = self.scrollView.contentOffset;
    newOffset.y = 0;
    [self.scrollView setContentOffset:newOffset animated:YES];
}

- (void)viewDidLoad {        
    [scroller setScrollEnabled:YES];
    [scroller setContentSize:CGSizeMake(320, 420)];    
    [super viewDidLoad];
}

Thanks.

> THUMBS UP FOR THE AWNSER THAT WAS GIVEN BY TOBI!!!

How about [self.scrollView setScrollsToTop:YES]; in whichever method you wanted this to happen? — iDev, Nov 06 '12 at 20:41

Tobi · Accepted Answer · 2012-11-07T18:46:41.117

8

Just use setContentOffset:animated:

UIScrollView *scrollView = ...;
CGPoint newOffset = scrollView.contentOffset;
newOffset.y = 0;
[scrollView setContentOffset:newOffset animated:YES];

Edit:

To use it like some kind of start animation you could do this in the scrollView's view controller:

- (void)viewDidLoad
{
    [super viewDidLoad];

    // ...

    CGPoint bottomOffset = CGPointMake(self.scrollView.contentOffset.x, self.scrollView.contentSize.height - self.scrollView.bounds.size.height);
    [self.scrollView setContentOffset:bottomOffset animated:NO];
}
- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    CGPoint newOffset = self.scrollView.contentOffset;
    newOffset.y = 0;
    [self.scrollView setContentOffset:newOffset animated:YES];
}

Edit 2 / 3:

To make the scrolling happen slower, use this:

- (void)viewDidLoad
{
    [super viewDidLoad];

    // ...

    CGPoint bottomOffset = CGPointMake(self.scrollView.contentOffset.x, self.scrollView.contentSize.height - self.scrollView.bounds.size.height);
    [self.scrollView setContentOffset:bottomOffset animated:NO];
}


- (void)viewDidAppear:(BOOL)animated
{    
    [super viewDidAppear:animated];

    float scrollDuration = 4.0;

    [UIView animateWithDuration:scrollDuration animations:^{
        self.scrollView.contentOffset = CGPointMake(self.scrollView.contentOffset.x, 0);
    }];
}

edited Nov 07 '12 at 18:46

answered Nov 06 '12 at 20:41

Tobi

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Well that depends on when you want the scrolling to happen :) – Tobi Nov 06 '12 at 20:43
actually I could put the code in viewdidappear? what do u mean? – MasterRazer Nov 06 '12 at 20:45
Do I have to replace the height with the height of the scrollview? – MasterRazer Nov 06 '12 at 20:52
the code assumes that your view controller has a property `scrollView`. If your's don't, you have to replace every `self.scrollView` in my example with a valid reference to your scrollView – Tobi Nov 06 '12 at 20:54
do you get a compiler error, or does the animation not work as you want? – Tobi Nov 06 '12 at 20:55
Ohh I forgot to say...I'm using storyboards and arc! Maybe this could be a problem? – MasterRazer Nov 06 '12 at 20:56
and are you able to scroll the scrollView "manually" by dragging? – Tobi Nov 06 '12 at 20:59
nope autolayout disabled but on my simulator it doesnt work at all just on my device it works fine (not the atutoscroll) just the srollview – MasterRazer Nov 06 '12 at 20:59
did you set the `contentSize` of your scrollView? – Tobi Nov 06 '12 at 21:01
you have to replace `self.scrollView` in your code with `self.scroller`. – Tobi Nov 06 '12 at 21:04
do you want the up-scrolling to happen **later** or **slower**? – Tobi Nov 06 '12 at 21:08
slower...yes just slower later actually doesnt matter – MasterRazer Nov 06 '12 at 21:09
that's a bit more complicated. I'll update my answer in a few minutes. – Tobi Nov 06 '12 at 21:12
Thank you...You saved my life twice... hahhahaha :D – MasterRazer Nov 06 '12 at 21:13
I think thats the longest comment compilation on stackoverflow ever :D – MasterRazer Nov 06 '12 at 21:15
...theres one thing...If the view loads the scrollview is n top. Then it springs on bottom and animate to top is there a programmiticaly way to disable this or should I replace the scrollview in the storyboard...means that I replace the content, that the buttom is shown if the view loads... – MasterRazer Nov 06 '12 at 21:37
jesus man you're better than steve jobs or the whole apple programmers on the dev. forum...they even dont help you...sad...(cry, cry) f***ing egoists! Hate those..But still luv you :D – MasterRazer Nov 06 '12 at 21:42
done. just move the code to scroll the scrollView to bottom in the `viewDidLoad` method – Tobi Nov 06 '12 at 21:42
I would be glad if you could help me with ths too see here http://stackoverflow.com/questions/13273435/automatic-paging-scrollview – MasterRazer Nov 07 '12 at 16:02

Automatic scrolling scrollview

.h

.m

> THUMBS UP FOR THE AWNSER THAT WAS GIVEN BY TOBI!!!

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