子视图的 UIStackView 不滚动答案

【问题标题】：UIStackView of subviews not Scrolling子视图的 UIStackView 不滚动
【发布时间】：2016-08-24 22:25:16
【问题描述】：

我有一个 UIScrollView，我在其中添加了一个 UIStackView 的子视图。子视图不可滚动，但如果我添加按钮而不是 UIView，则堆栈视图可滚动。此代码出现在拆分视图控制器的详细视图中。关于为什么子视图不滚动的任何想法？顺便说一句，detailItem 将携带索引，但现在我正在硬编码索引 [4] 以获得有保证的长滚动列表。

import UIKit

class DetailViewController: UIViewController {

    var scrollView: UIScrollView!
    var stackView: UIStackView!

    var detailItem: AnyObject? {
        didSet {
        // Update the view.
     //   self.configureView()
     //   print("didSet: configureView")
        }
    }

override func viewDidLoad() {
    super.viewDidLoad()

    scrollView = UIScrollView()
    scrollView.translatesAutoresizingMaskIntoConstraints = false
    view.addSubview(scrollView)

    view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|[scrollView]|", options: .AlignAllCenterX, metrics: nil, views: ["scrollView": scrollView]))
    view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|[scrollView]|", options: .AlignAllCenterX, metrics: nil, views: ["scrollView": scrollView]))


    stackView = UIStackView()
    stackView.translatesAutoresizingMaskIntoConstraints = false
    stackView.axis = .Vertical

    scrollView.addSubview(stackView)

    scrollView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|[stackView]|", options: NSLayoutFormatOptions.AlignAllCenterX, metrics: nil, views: ["stackView": stackView]))
    scrollView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|[stackView]", options: NSLayoutFormatOptions.AlignAllCenterX, metrics: nil, views: ["stackView": stackView]))
 /*
    for _ in 1 ..< 100 {
        let vw = UIButton(type: UIButtonType.System)
        vw.setTitle("Button", forState: .Normal)
        stackView.addArrangedSubview(vw)
    }
 */

    let selectedGroup: Group = GroupArray[4]

    let descriptorsArray = selectedGroup.descriptorsArray

    for descriptor in descriptorsArray {
        // Create a subview for each descriptor

        let subView = UIView()
        subView.frame = CGRectMake(0 , 0, self.view.frame.width-10, 50)
        subView.backgroundColor = UIColor.yellowColor()

        subView.heightAnchor.constraintEqualToConstant(50.0).active = true
        // Create a label for Descriptor subview
        let label = UILabel(frame: CGRectMake(20, 0, 200, 46))
        label.text = descriptor.name
        label.font = UIFont.boldSystemFontOfSize(22.0)
        label.textAlignment = .Left
        label.textColor = UIColor.brownColor()

        subView.addSubview(label)
        // Create a button for Checkbox

        stackView.addArrangedSubview(subView)

     }
}

}

【问题讨论】：

标签： ios swift uiscrollview uistackview

【解决方案1】：

你缺少一个约束：

scrollView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:|[stackView]|", options: NSLayoutFormatOptions.AlignAllCenterX, metrics: nil, views: ["stackView": stackView]))
scrollView.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|[stackView]", options: NSLayoutFormatOptions.AlignAllCenterX, metrics: nil, views: ["stackView": stackView]))

您忘记将堆栈视图固定到滚动视图的底部。没有它，滚动视图就没有contentSize。没有contentSize，就不能滚动。

【讨论】：

谢谢，马特。你让我想起了我之前尝试过的内容，但它不起作用，因为我之前没有适当的约束，我猜。我添加了这一行并滚动：scrollView.contentSize = CGSizeMake(400, 1000)

【解决方案2】：

@Jolly 你可以试试ScrollableStackView：https://github.com/gurhub/ScrollableStackView

它是 Objective-C 和 Swift 兼容的库。可通过CocoaPods 获得。

示例代码

import ScrollableStackView

var scrollable = ScrollableStackView(frame: view.frame)
view.addSubview(scrollable)

// add your views with 
let rectangle = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 55))
rectangle.backgroundColor = UIColor.blue
scrollable.stackView.addArrangedSubview(rectangle)
// ...

【讨论】：