UIScrollView setting page size dynamically

Question

I've done quite a bit of looking into this but have been unsuccessful in finding a solution.

I have a UIScrollView called scrollView inside of UIView. I'm using this scrollView in pagingEnabled mode. Inside of scrollView, I have 3 different views created programmatically. Inside of these 3 different views, I have a bunch of stuff(UILabel,UITextView etc.). All of the views contents are dynamic and determined at runtime.So, i really don't know scrollView.contentSize. If i give the content size of this scrollView,Sometimes ,I have a screen with white blank at the botton of the screen when user scrolls down. My question is : Can i set the content size dynamically for each single page of this scrollView? For example,for page 1 :

self.scrollViewNews.contentSize = CGSizeMake(constant1,constant2);

And set something else for page 2 as well .

score 3 · Accepted Answer · answered Aug 15 '12 at 14:28

I think you're confused about contentSize vs the paging size. The paging size is always the size of the scrollView bounds, and isn't a property you can otherwise set. That is, when you swipe left/right it will "page" by the width of the scrollview.

contentSize is the size of the virtual bounding box of all the subviews within the scrollview. This only serves to limit how far the scrollview will scroll, and for paging, how many times it will page, i.e. contentSize.width / bounds.size.width.

Assuming the scrollView isn't zoomed in/out (zoomScale = 1.0) then you need to position and size your subviews on the virtual 'page boundaries'. They can take up the full page boundary (be sized to match scrollview.bounds) or be inset. If you have some content that is larger/smaller then you'll have to decide if you want to change the scale of that content or size it up/down within the page bounds.

score 1 · Answer 2 · answered Aug 15 '12 at 09:32

1

Yes you can dynamically set the content size of the scrollView. Also You can use this method:

self.scrollViewNews.contentSize = CGSizeMake(constant1,constant2);

Nothing wrong this method. You are seeing the blank space at bottom because you ares setting the height of the scrollView's contentSize to a larger value than it's content. That's the issue. Adjust the height according to the contents, blank space will go.

answered Aug 15 '12 at 09:32

Midhun MP

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With this method,i'm not able to change content size for a single page.This method makes all of the page's content size constant1,constant2.I want page1 and page2 have different content size. So,i cannot use this method. – limon Aug 15 '12 at 09:37

score 1 · Answer 3 · answered Aug 15 '12 at 11:39

please, try to get the actual content size from the current content.

the content must be some inherited class from the UIView and it has a frame.size.width and frame.size.height property.

you can use those to set the contentSize of your UIScrollview for the current content at that time when you add the content to the UIScrollView.

Shamsudheen TK · Answer 4 · 2012-08-15T09:41:19.350

0

Yeah. You can set the scrollView size dynamically through

scroller.contentSize = CGSizeMake(1650, 2000);

You can use the following property to set the dynamic frame for each pages

[urScrollView scrollRectToVisible:frame animated:YES];

if you are using pagingEnabled = YES for your scrollview

The below UIScrollViewDelegate delegate will adjust the page and content

-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{

    int page = urScrollView.contentOffset.x/urScrollView.frame.size.width;
    pageControl.currentPage = page;
}

//pager action
- (IBAction)changePage:(id)sender{

    int page = pageControl.currentPage;
    CGRect frame = urScrollView.frame;
    frame.origin.x = frame.size.width * page;
    frame.origin.y  = 0;
    [urScrollView scrollRectToVisible:frame animated:YES];
}

please look at this sample app

edited Aug 15 '12 at 09:41

answered Aug 15 '12 at 09:35

Shamsudheen TK

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It's not what i'm looking for either.Take a look at a sample app,all of the pages have the same size.scroller.contentSize = CGSizeMake(1650, 2000); this is what i use for now,but as u imagine,if the content size smaller than 1650,2000 which is the most case,user is going to see the white blank space at the bottom of the screen.Do you understand what i mean ? – limon Aug 15 '12 at 10:07
oh.. better make sure to set the contentSize is always larger than the scrollView frame. Else please reset the scrollView Frame (smaller than contentSize) again before going to set the contentSize . please do this and what about the method scrollRectToVisible method ?? – Shamsudheen TK Aug 15 '12 at 11:03

score 0 · Answer 5 · answered Feb 13 '13 at 11:44

Try out this.

- (void)viewDidLoad
{
    float sizeOfContent = 0;
    UIView *lLast = [scrollView.subviews lastObject];
    NSInteger wd = lLast.frame.origin.y;
    NSInteger ht = lLast.frame.size.height;

    sizeOfContent = wd+ht;

    scrollView.contentSize = CGSizeMake(scrollView.frame.size.width, sizeOfContent);
}

UIScrollView setting page size dynamically

5 Answers5