以编程方式将UIScrollView滚动到Swift中的子UIView(子视图)的顶部

Question

我的UIScrollView中有几个屏幕内容,只能垂直滚动.

我想以编程方式滚动到包含在其层次结构中的某个视图.

UIScrollView移动,以便子视图位于UIScrollView的顶部(动画或不动画)

Answer 1

这是我最后写的扩展.

用法:

从我的viewController调用,self.scrollView是UIScrollView的出口,self.commentsHeader是其中的一个视图,靠近底部:

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

码:

您只需要scrollToView方法,但也可以使用scrollToBottom/scrollToTop方法,因为您可能也需要这些方法,但可以随意删除它们.

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)
        }
    }

}

Answer 2

 scrollView.scrollRectToVisible(CGRect(x: x, y: y, width: 1, height:
1), animated: true)

要么

scrollView.setContentOffset(CGPoint(x: x, y: y), animated: true)

另一种方式是

scrollView.contentOffset = CGPointMake(x,y);

我用这样的动画做到了

[UIView animateWithDuration:2.0f delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
scrollView.contentOffset = CGPointMake(x, y); }
completion:NULL];