UIScrollView

let width = self.view.frame.width
let height = self.view.frame.height
        
let scrollView = UIScrollView(frame: CGRect(x: 0.0, y: 0.0, width: width, height: height))
scrollView.backgroundColor = UIColor.orange
scrollView.contentSize = CGSize(width: 2 * width, height: 2 * height)
self.view.addSubview(scrollView)

代理方法

• 正在滚动

scrollViewDidScroll

• 将要开始拖拽

scrollViewWillBeginDragging