Programmatically scroll a UIScrollView to the top of a child UIView (subview) in Swift

Question

I have a few screens worth of content within my UIScrollView which only scrolls vertically.

I want to programmatically scroll to a view contained somewhere in it's hierarchy.

The UIScrollView move so that the child view is at the top of the UIScrollView (either animated or not)

Answer 1

Here's an extension I ended up writing.

Usage:

Called from my viewController, self.scrollView is an outlet to the UIScrollView and self.commentsHeader is a view within it, near the bottom:

self.scrollView.scrollToView(self.commentsHeader, animated: true) 

Code:

You only need the scrollToView method, but leaving in scrollToBottom / scrollToTop methods too as you'll probably need those too, but feel free to delete them.

extension UIScrollView {      // Scroll to a specific view so that it's top is at the top our scrollview     func scrollToView(view:UIView, animated: Bool) {         if let origin = view.superview {             // Get the Y position of your child view             let childStartPoint = origin.convertPoint(view.frame.origin, toView: self)             // Scroll to a rectangle starting at the Y of your subview, with a height of the scrollview             self.scrollRectToVisible(CGRect(x:0, y:childStartPoint.y,width: 1,height: self.frame.height), animated: animated)         }     }      // Bonus: Scroll to top     func scrollToTop(animated: Bool) {         let topOffset = CGPoint(x: 0, y: -contentInset.top)         setContentOffset(topOffset, animated: animated)     }      // Bonus: Scroll to bottom     func scrollToBottom() {         let bottomOffset = CGPoint(x: 0, y: contentSize.height - bounds.size.height + contentInset.bottom)         if(bottomOffset.y > 0) {             setContentOffset(bottomOffset, animated: true)         }     }  }