Question

如何让UIScrollView开始从上到下滚动。当我向下滑动（向下）时，它将首先向下滚动而不是向上滚动并消失。我现在拥有的是，我可以先向上滚动然后向下滚动，向下滚动它会消失。这是我的代码 -

func scrollViewDidScroll(_ scrollView: UIScrollView) {

        //for toogle swipe view
        if scrollView.contentOffset.y < 120 {
            self.swipeMsgView.isHidden = false
        }else {
            self.swipeMsgView.isHidden = true
        }
        //for making bottom inset
        if scrollView.contentOffset.y < 190 {
            var contentInset:UIEdgeInsets = scrollView.contentInset
            contentInset.bottom = scrollView.contentOffset.y-100
            scrollView.contentInset = contentInset
        }
        //when swipe down
        if scrollView.contentOffset.y == 0 {
            if !isScrollDownFirstTime{
                UIView.animate(withDuration: 0.5, animations: {
                    self.dismiss(animated: true, completion: nil)
                })
            }
        }
        //for tracking first time scrolling
        if scrollView.contentOffset.y > 150 {
            isScrollDownFirstTime = false
        }
    }

工作正常。但是我想在用户首先滑动或向下滚动时消失视图（滑动手势不起作用）。使用这个现有功能有没有优雅的方法呢？谢谢。

Answer 1

@Serg Smyk，这是我解决问题的方法。

    fileprivate var isScrollDownFirstTime = true

    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        print("Content y offet : \(scrollView.contentOffset.y)")
        //for toogle swipe view
        if scrollView.contentOffset.y < 120 {
            self.swipeMsgView.isHidden = false
        } else {
            self.swipeMsgView.isHidden = true
        }
        
        //for making bottom inset
        if scrollView.contentOffset.y < 190 {
            var contentInset:UIEdgeInsets = scrollView.contentInset
            contentInset.bottom = scrollView.contentOffset.y-100
            scrollView.contentInset = contentInset
        }
        
        //when swipe down
        if scrollView.contentOffset.y == 0 {
            print(CLASS_NAME+" -- scrollViewDidScroll() -- contentOffset.y = 0")
            if !isScrollDownFirstTime{
                UIView.animate(withDuration: 0.5, animations: {
                    self.dismiss(animated: true, completion: nil)
                })
            }
        }

        if scrollView.contentOffset.y < 1 {
            print(CLASS_NAME+" -- scrollViewDidScroll() -- contentOffset.y<0")
            UIView.animate(withDuration: 0.5, animations: {
                self.dismiss(animated: true, completion: nil)
            })
        }
        //for tracking first time scrolling
        if scrollView.contentOffset.y > 150 {
            isScrollDownFirstTime = false
        }
    }

首先滑动/向下滚动将消失视图

1 个答案: