I got question about UIScrollview
.
The story is I have a UIView
named ChartsView which I re-draw it myself by override method drawRect()
. The content of drawing was generated dynamically. So I do not know its size until runtime. The question is how/where can I set its super view's (scrollView) content size dynamically?Any idea about that?
- (void)viewDidLoad
{
[super viewDidLoad];
// not this way. it's fixed size.....
ChartsView *chartsView = [[ChartsView alloc]initWithFrame:CGRectMake(0, 0, 320, 800)];
self.scrollView.contentSize = chartsView.frame.size;
[self.scrollView addSubview:chartsView];
}
One more easy way
- (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); }
It is not 100% guaranteed that the last object in scrollView.subviews array will return the highest y-origin object in your scroll view. The subviews array is arranged by Z-Index (i.e the last object in the subviews array will be the object stacked the highest and will be the top-most subview in the scroll view's subviews. Instead it is more accurate to use a basic sort function to iterate through the subviews and get the object with the highest y-origin.
Swift 4
extension UIScrollView {
func updateContentView() {
contentSize.height = subviews.sorted(by: { $0.frame.maxY < $1.frame.maxY }).last?.frame.maxY ?? contentSize.height
}
}
Usage (in viewDidLayoutSubviews
or whenever your content size updates):
myScrollView.updateContentView()
swift (2.0)
@IBOutlet weak var btnLatestButton: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
let height = btnLatestButton.frame.size.height
let pos = btnLatestButton.frame.origin.y
let sizeOfContent = height + pos + 10
scrollview.contentSize.height = sizeOfContent
}
Above ofcourse is when you just have a fixed amount of views on your scrollview. IOS Rocks method is available but was not good for me, created more space then I needed.
let lastView : UIView! = scrollview.subviews.last
let height = lastView.frame.size.height
let pos = lastView.frame.origin.y
let sizeOfContent = height + pos + 10
scrollview.contentSize.height = sizeOfContent
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