UIScrollView setting page size dynamically - iphone

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 .

Answer 1

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.

Answer 2

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.

Answer 3

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.

Answer 4

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

Answer 5

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);
}