在我的例子中，stackView内的视图数量是可变的，我想将项目居中。例如，在stackView中有一个视图，我希望这个视图位于屏幕中央，如果所有的视图都不适合屏幕，我希望视图是可滚动的。

这是我的视图的层次结构。

所以我为按钮设置了一个固定的宽度，然后，为stackView:

与按钮相同的固定宽度，但优先级为650。 对齐X中心到containerView 尾随>= 0和前导>= 0到containerView 底部和顶部空间到containerView

对于containerView:

拖尾，领先，底部，顶部，等高，等宽(250优先级)到superview 固定的高度

对于scrollView:

尾随，领先，底部，顶部到父视图

scrollView也嵌入到具有前导和后导约束的视图中。

关于我用来解决这个问题的代码:

for index in 0...array.count - 1 {

      if index == 0 {
          firstButton.setTitle(title, for: .normal)
      } else {
          let button = UIButton()
          button.setTitle(title, for: .normal)
          stackView.addArrangedSubview(button)
          stackView.setNeedsLayout()
      }
}
containerView.layoutIfNeeded()
        
stackView.distribution = .fillEqually
stackView.spacing = 10
stackView.alignment = .fill

当使用故事板做这件事时，每个人似乎都错过了修复乘数! 当你按照上面的步骤在任何人教程和重置常数为0，同时检查乘数，并将其重置为1，它将采取了一些其他因素时，视觉链接保持到位

我发现我可以在UIStackView中简单地做一个loooooooooong文本块挤压或拉伸

简单的 向滚动视图添加约束 左上右下，弊为0

向指向滚动条Content Layout Guide的堆栈视图添加约束

然后从框架布局指南中添加等宽或等高的约束。 选择:宽度如果内容需要垂直滚动，高度如果它需要水平滚动。

这是关键。编辑每个约束并将常数重置为0并将乘数设置回1!!!!!

如果你不这样做，它就会摇摇欲坠

如果它工作，你可以点击内部内容和鼠标滚动

苹果的自动布局指南包括了一个关于使用滚动视图的完整部分。一些相关片段:

Pin the content view’s top, bottom, leading, and trailing edges to the scroll view’s corresponding edges. The content view now defines the scroll view’s content area. (Optional) To disable horizontal scrolling, set the content view’s width equal to the scroll view’s width. The content view now fills the scroll view horizontally. (Optional) To disable vertical scrolling, set the content view’s height equal to the scroll view’s height. The content view now fills the scroll view horizontally.

此外:

你的布局必须完全定义内容视图的大小(除了 . ...当内容视图比滚动视图高时，滚动视图允许垂直滚动。当内容视图比滚动视图宽时，滚动视图启用水平滚动。

To summarize, the scroll view's content view (in this case, a stack view) must be pinned to its edges and have its width and/or height otherwise constrained. That means that the contents of the stack view must be constrained (directly or indirectly) in the direction(s) in which scrolling is desired, which might mean adding a height constraint to each view inside a vertically scrolling stack view, for example. The following is an example of how to allow for vertical scrolling of a scroll view containing a stack view:

// Pin the edges of the stack view to the edges of the scroll view that contains it
stackView.topAnchor.constraint(equalTo: scrollView.topAnchor).isActive = true
stackView.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor).isActive = true
stackView.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor).isActive = true
stackView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor).isActive = true

// Set the width of the stack view to the width of the scroll view for vertical scrolling
stackView.widthAnchor.constraint(equalTo: scrollView.widthAnchor).isActive = true

水平滚动(UIScrollView中的UIStackView)

用于水平滚动。首先，创建一个UIStackView和一个UIScrollView，并按以下方式将它们添加到您的视图中:

let scrollView = UIScrollView()
let stackView = UIStackView()

scrollView.addSubview(stackView)
view.addSubview(scrollView)

记住在UIStackView和UIScrollView上设置translatesAutoresizingMaskIntoConstraints为false:

stackView.translatesAutoresizingMaskIntoConstraints = false
scrollView.translatesAutoresizingMaskIntoConstraints = false

为了让一切正常工作，UIStackView的尾随，领先，顶部和底部锚应该等于UIScrollView锚:

stackView.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor).isActive = true
stackView.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor).isActive = true
stackView.topAnchor.constraint(equalTo: scrollView.topAnchor).isActive = true
stackView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor).isActive = true

但是UIStackView的宽度锚点必须等于或大于UIScrollView锚点的宽度:

stackView.widthAnchor.constraint(greaterThanOrEqualTo: scrollView.widthAnchor).isActive = true

现在锚定你的UIScrollView，例如:

scrollView.heightAnchor.constraint(equalToConstant: 80).isActive = true
scrollView.widthAnchor.constraint(equalTo: view.widthAnchor).isActive = true

scrollView.bottomAnchor.constraint(equalTo:view.safeAreaLayoutGuide.bottomAnchor).isActive = true
scrollView.leadingAnchor.constraint(equalTo:view.leadingAnchor).isActive = true
scrollView.trailingAnchor.constraint(equalTo:view.trailingAnchor).isActive = true 

接下来，我建议尝试以下设置UIStackView对齐和分布:

topicStackView.axis = .horizontal
topicStackView.distribution = .equalCentering
topicStackView.alignment = .center

topicStackView.spacing = 10

最后，你需要使用addArrangedSubview:方法来添加子视图到你的UIStackView。

文本Insets

另一个你可能会发现有用的特性是，因为UIStackView保存在UIScrollView中，你现在可以访问文本insets，使事情看起来更漂亮一点。

let inset:CGFloat = 20
scrollView.contentInset.left = inset
scrollView.contentInset.right = inset

// remember if you're using insets then reduce the width of your stack view to match
stackView.widthAnchor.constraint(greaterThanOrEqualTo: topicScrollView.widthAnchor, constant: -inset*2).isActive = true

这里投票最多的答案中的约束条件对我来说是有效的，我已经将在我的故事板中创建的约束条件的图像粘贴在下面。

我确实提到了两个问题，但其他人应该注意:

After adding constraints similar to those in in the accepted answer, I'd get the red autolayout error Need constraints for: X position or width. This was solved by adding a UILabel as a subview of the stack view. I'm adding the subviews programmatically, so I originally had no subviews on the storyboard. To get rid of the autolayout errors, add a subview to the storyboard, then remove it on load before adding your real subviews and constraints. I originally attempted to add UIButtons to the UIStackView. The buttons and views would load, but the scroll view would not scroll. This was solved by adding UILabels to the Stack View instead of buttons. Using the same constraints, this view hierarchy with the UILabels scrolls but the UIButtons does not. I'm confused by this issue, as the UIButtons do seem to have an IntrinsicContentSize (used by the Stack View). If anyone knows why the buttons don't work, I'd love to know why.

下面是我的视图层次结构和约束，供参考:

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

它是Objective-C和Swift兼容的库。它可以通过CocoaPods获得。

样本代码(Swift)

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)
// ...

样例代码(Objective-C)

@import ScrollableStackView

ScrollableStackView *scrollable = [[ScrollableStackView alloc] initWithFrame:self.view.frame];
scrollable.stackView.distribution = UIStackViewDistributionFillProportionally;
scrollable.stackView.alignment = UIStackViewAlignmentCenter;
scrollable.stackView.axis = UILayoutConstraintAxisVertical;
[self.view addSubview:scrollable];

UIView *rectangle = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 100, 55)];
[rectangle setBackgroundColor:[UIColor blueColor]];

// add your views with
[scrollable.stackView addArrangedSubview:rectangle]; 
// ...