ios - Swift UIScrollView 在没有 pagingEnabled 的情况下捕捉到 subview 宽度

Question

当滑动捕捉到其 subview 宽度时，我如何实现 UIScrollView。我需要它表现得像 pagingEnabled 但我无法启用分页，因为我需要我的整个 View 可以滑动滚动。如果我执行 pagingEnable 这是不可能的，因为 ScrollView 边界将更改为 subview 宽度。

有什么办法可以做到吗？ please check the image for more details

import UIKit

class ViewController: UIViewController{

  var navigationScroller: UIScrollView!
  var contentScroller: UIScrollView!
  var navContainer: UIView!
  var contentContainer: UIView!
  var selfWidth:CGFloat?
  var navigationLabels = ["EVENTS", "MEMBERS", "SECTORS", "ORGANIZATIONS", "SEARCH", "EVENTS", "MEMBERS"]
 private var buttonsTextFontAndSize: UIFont = UIFont(name:     "HelveticaNeue-Light", size: 14)!
override func viewDidLoad() {

    super.viewDidLoad()
    selfWidth = self.view.frame.width
    let frameWidth = self.view.frame.width
    let frameHeight = self.view.frame.height
    //let navscrollPosition = CGFloat( (frameWidth/2) - (75.0/2) )


    navContainer = UIView(frame: CGRectMake(0.0, 75.0, frameWidth, 40.0))
    navContainer.backgroundColor = UIColor(red:0,  green:0.302,  blue:0.522, alpha:1)



    navigationScroller = UIScrollView(frame: CGRectMake(0.0, 0.0, frameWidth, 40.0))
    navigationScroller.backgroundColor = UIColor.clearColor()
    navigationScroller.pagingEnabled = false
    navigationScroller.showsHorizontalScrollIndicator = false
    navigationScroller.showsVerticalScrollIndicator = false
    navigationScroller.clipsToBounds = false
    navigationScroller.contentInset = UIEdgeInsetsZero
    //navigationScroller.userInteractionEnabled = false
    //navigationScroller.

    addNavigationLabels(navigationScroller)
    self.view.addSubview(navContainer)
    navContainer.addSubview(navigationScroller)
    navigationScroller.contentSize = CGSize(width: 150.0 * CGFloat(navigationLabels.count),height: 40.0)
    navigationScroller.contentOffset = CGPoint(x: 170.0, y:0.0)


    contentContainer = UIView(frame: CGRectMake(0.0, 115.0, frameWidth, frameHeight-115.0))
    contentContainer.backgroundColor = UIColor.clearColor()

    contentScroller = UIScrollView(frame: CGRectMake(0.0, 0.0, frameWidth, frameHeight-115.0))
    contentScroller.backgroundColor = UIColor.clearColor()
    contentScroller.pagingEnabled = true
    contentScroller.showsHorizontalScrollIndicator = false
    contentScroller.showsVerticalScrollIndicator = false
    contentScroller.clipsToBounds = true
    contentScroller.contentInset = UIEdgeInsetsZero
    //contentScroller.addSubview(navContainer)
    addContents(contentScroller)
    self.view.addSubview(contentContainer)
    contentContainer.addSubview(contentScroller)
    contentScroller.contentSize = CGSize(width: frameWidth * CGFloat(navigationLabels.count),
        height: frameHeight-115.0)
    //contentScroller.delegate = self
    navigationScroller.delegate = self



}

//MARK: -View Appeared function
override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(true)
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}

// MARK: -Adding navigation labels fron navigation labels array
private func addNavigationLabels(navScrollView:UIScrollView){
    var buttonsXPosition: CGFloat = 0
    var buttonNumber = 0

    for navLabel in navigationLabels {
        var navButton: UIButton!
        let red = CGFloat(buttonNumber) - 0.9
        let frameWidth = self.view.frame.width
        navButton = UIButton(frame: CGRectMake(buttonsXPosition, 0, frameWidth/3, 40.0))
        navButton.titleLabel!.font = buttonsTextFontAndSize
        navButton.contentHorizontalAlignment = .Center

        navButton.backgroundColor = UIColor(red:red  ,  green:0.114,  blue:0.286, alpha:1)
        navButton.setTitle(navLabel, forState: UIControlState.Normal)
        navButton.addTarget(self, action: "buttonAction:", forControlEvents: UIControlEvents.TouchUpInside)
        navScrollView.addSubview(navButton)

        buttonsXPosition = frameWidth/3 + buttonsXPosition
        buttonNumber++
    }
}

func buttonAction(sender:UIButton!){
    print("pressed")
}

// MARK: -Adding navigation labels fron navigation labels array
private func addContents(contentScroller:UIScrollView){
    var buttonsXPosition: CGFloat = 0
    var buttonNumber = 0
    let frameWidth = self.view.frame.width
    let frameHeight = self.view.frame.height
    for navLabel in navigationLabels {
        var navButton: UIButton!
        navButton = UIButton(frame: CGRectMake(buttonsXPosition, 40.0, frameWidth, frameHeight-155))
        navButton.titleLabel!.font = buttonsTextFontAndSize
        navButton.contentHorizontalAlignment = .Center
        navButton.backgroundColor = UIColor.darkGrayColor()
        navButton.setTitle(navLabel, forState: UIControlState.Normal)
        contentScroller.addSubview(navButton)
        buttonsXPosition = frameWidth + buttonsXPosition
        buttonNumber++

    }
    } 
}

app view

Answer 1

您可以实现UIScrollViewDelegate 的方法scrollViewWillEndDragging:withVelocity:targetContentOffset:并修改偏移量，它将完成减速以匹配您希望的宽度。

像这样:

class ScrollSample: NSObject, UIScrollViewDelegate {
    func scrollViewWillEndDragging(scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {

        let targetOffset = targetContentOffset.memory.x
        // Round the offset to be a multiple of scrollview width
        let roundedOffset = round(targetOffset / scrollView.frame.width) * scrollView.frame.width
        targetContentOffset.memory = CGPoint(x: roundedOffset, y: 0)
    }
}