可变宽度StackView?

Question

这是我的代码:

import UIKit
class DocumentViewController: UIViewController, UIScrollViewDelegate {

func viewForZooming(in scrollView: UIScrollView) -> UIView? {
return scrollViewContainer
}

func scrollViewDidZoom(_ scrollView: UIScrollView) {
let scrollViewSize = scrollView.bounds.size
let scrollViewContainerSize = scrollViewContainer.frame.size
let verticalPadding = scrollViewContainerSize.height < scrollViewSize.height ? (scrollViewSize.height - scrollViewContainerSize.height) / 2 : 0
let horizontalPadding = scrollViewContainerSize.width < scrollViewSize.width ? (scrollViewSize.width - scrollViewContainerSize.width) / 2 : 0
scrollView.contentInset = UIEdgeInsets(top: verticalPadding, left: horizontalPadding, bottom: verticalPadding, right: horizontalPadding)
}

let scrollView: UIScrollView = {
let scrollView = UIScrollView()
scrollView.translatesAutoresizingMaskIntoConstraints = false
scrollView.minimumZoomScale = 0.1
scrollView.maximumZoomScale = 4.0
scrollView.zoomScale = 1.0
return scrollView
}()

let scrollViewContainer: UIStackView = {
let view = UIStackView()
view.translatesAutoresizingMaskIntoConstraints = false
view.axis = .vertical
view.spacing = 15
return view
}()
override func viewDidLoad() {
super.viewDidLoad()
scrollView.delegate = self
view.backgroundColor = .gray
view.addSubview(scrollView)
scrollView.addSubview(scrollViewContainer)

let uiview1 = UIView(frame: .zero)
uiview1.heightAnchor.constraint(equalToConstant: 1000).isActive = true
uiview1.widthAnchor.constraint(equalToConstant: 1000).isActive = true
scrollViewContainer.addArrangedSubview(uiview1)
uiview1.backgroundColor = .white

let uiview2 = UIView(frame: .zero)
uiview2.heightAnchor.constraint(equalToConstant: 1000).isActive = true
uiview2.widthAnchor.constraint(equalToConstant: 1000).isActive = true
scrollViewContainer.addArrangedSubview(uiview2)
uiview2.backgroundColor = .white

let uiview3 = UIView(frame: .zero)
uiview3.heightAnchor.constraint(equalToConstant: 1000).isActive = true
uiview3.widthAnchor.constraint(equalToConstant: 1000).isActive = true
scrollViewContainer.addArrangedSubview(uiview3)
uiview3.backgroundColor = .white

let uiview4 = UIView(frame: .zero)
uiview4.heightAnchor.constraint(equalToConstant: 1000).isActive = true
uiview4.widthAnchor.constraint(equalToConstant: 1000).isActive = true
scrollViewContainer.addArrangedSubview(uiview4)
uiview4.backgroundColor = .white

let uiview5 = UIView(frame: .zero)
uiview5.heightAnchor.constraint(equalToConstant: 1000).isActive = true
uiview5.widthAnchor.constraint(equalToConstant: 2000).isActive = true
scrollViewContainer.addArrangedSubview(uiview5)
uiview5.backgroundColor = .white

showBounds()
setConstraints()
}

func setConstraints() {
scrollView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
scrollView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
scrollView.topAnchor.constraint(equalTo: view.topAnchor).isActive = true
scrollView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
scrollViewContainer.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor).isActive = true
scrollViewContainer.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor).isActive = true
scrollViewContainer.topAnchor.constraint(equalTo: scrollView.topAnchor).isActive = true
scrollViewContainer.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor).isActive = true

}

func showBounds() {
view.layer.borderWidth = 5.0
view.layer.borderColor = UIColor.blue.cgColor
scrollViewContainer.layer.borderWidth = 5.0
scrollViewContainer.layer.borderColor = UIColor.red.cgColor
scrollView.layer.borderWidth = 3.0
scrollView.layer.borderColor = UIColor.yellow.cgColor
}
}

这段代码给出了以下行为:https://i.stack.imgur.com/gNxnD.gif

你可以看到，尽管我在viewDidLoad中做的最后一个测试UIView的宽度是2000，但它最终由于某种原因被切断了，就好像它的宽度是1000。另外，如果我改变最后一个视图的宽度为500，我得到这个行为。

所以看起来scrollViewContainer(?)正在调整到那些测试uiview的最小宽度。我想要的只是允许不同大小的视图，默认宽度是最宽的子视图，就像这个模型一样。

Answer 1

您需要在堆栈视图中添加'alignment'。请试试这个:

let scrollViewContainer: UIStackView = {
let view = UIStackView()
view.translatesAutoresizingMaskIntoConstraints = false
view.axis = .vertical
view.alignment = .center
view.spacing = 15
return view
}()