以編程方式將UIScrollView滾動到Swift中的子UIView（子視圖）的頂部

Question

我的UIScrollView中只有幾個屏幕值得我的內容垂直滾動。

我想以編程方式滾動到包含在它的層次結構中某處的視圖。

的UIScrollView的移動，使得孩子的看法是在UIScrollView的頂部（或動畫與否）

Answer 1

下面是一個擴展我結束了寫作。

用法：

從我的viewController調用，self.scrollView是出口到的UIScrollView和self.commentsHeader是在其內的圖，靠近底部：

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

代碼：

您只需要scrollToView方法，但在scrollToBottom/scrollToTop方法也可能需要這些，但隨時刪除它們。

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(CGRectMake(0, childStartPoint.y, 1, 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.setContentOffset(CGPoint, animated: Bool) 

其中該點的y座標是你要比較顯示到滾動視圖的內容視圖視圖的幀的y座標。

Answer 3

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

或

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

另一種方式是

scrollView.contentOffset = CGPointMake(x,y); 

，我和動畫這樣

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

Answer 4

對於滾動到頂部或底部，完成做動畫

// MARK: - UIScrollView extensions 

extension UIScrollView { 
    /// Animate scroll to bottom with completion 
    /// 
    /// - Parameters: 
    /// - duration: TimeInterval 
    /// - completion: Completion block 
    func animateScrollToBottom(withDuration duration: TimeInterval, 
          completion:    (()->())? = nil) { 

     UIView.animate(withDuration: duration, animations: { [weak self] in 
      self?.setContentOffset(CGPoint.zero, animated: false) 
      }, completion: { finish in 
       if finish { completion?() } 
     }) 
    } 

    /// Animate scroll to top with completion 
    /// 
    /// - Parameters: 
    /// - duration: TimeInterval 
    /// - completion: Completion block 
    func animateScrollToBottomTop(withDuration duration: TimeInterval, 
            completion:    (()->())? = nil) { 
     UIView.animate(withDuration: duration, animations: { [weak self] in 
      guard let `self` = self else { 
       return 
      } 
      let desiredOffset = CGPoint(x: 0, y: -self.contentInset.top) 
      self.setContentOffset(desiredOffset, animated: false) 

      }, completion: { finish in 
       if finish { completion?() } 
     }) 
    } 
} 

Answer 5

這是我的答案，這是迅速。這將無限滾動scrollview頁面。

private func startBannerSlideShow() 
{ 
UIView.animate(withDuration: 6, delay: 0.1, options: .allowUserInteraction, animations: { 
    scrollviewOutlt.contentOffset.x = (scrollviewOutlt.contentOffset.x == scrollviewOutlt.bounds.width*2) ? 0 : scrollviewOutlt.contentOffset.x+scrollviewOutlt.bounds.width 
}, completion: { (status) in 
    self.startBannerSlideShow() 
}) 
}