您可以通过以下解决方法来实现。代替间距，为每个空间添加一个新的UIView()，这将是一个可拉伸的空间。然后只需在这些“空间”的高度之间添加约束，这将根据您想要的乘数将它们的高度约束在一起，例如：
space1.heightAnchor.constraint(equalTo: space2.heightAnchor, multiplier: 2).isActive = true
为了让它发挥作用，我认为您必须添加一个约束，以在有可用空间的情况下尝试拉伸这些空间：
let stretchingConstraint = space1.heightAnchor.constraint(equalToConstant: 1000)
// lowest priority to make sure it wont override any of the rest of constraints and compression resistances
stretchingConstraint.priority = UILayoutPriority(rawValue: 1)
stretchingConstraint.isActive = true
“正常”内容视图必须具有固有大小或显式约束设置其高度才能正常工作。
这是一个例子：
class MyViewController: UIViewController {
fileprivate let stack = UIStackView()
fileprivate let views = [UIView(), UIView(), UIView(), UIView()]
fileprivate let spaces = [UIView(), UIView(), UIView()]
override func viewDidLoad() {
super.viewDidLoad()
self.view.backgroundColor = .white
self.view.addSubview(stack)
// let stack fill the whole view
stack.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
stack.topAnchor.constraint(equalTo: self.view.topAnchor),
stack.bottomAnchor.constraint(equalTo: self.view.bottomAnchor),
stack.leftAnchor.constraint(equalTo: self.view.leftAnchor),
stack.rightAnchor.constraint(equalTo: self.view.rightAnchor),
])
stack.alignment = .fill
// distribution must be .fill
stack.distribution = .fill
stack.spacing = 0
stack.axis = .vertical
for (index, view) in views.enumerated() {
stack.addArrangedSubview(view)
view.translatesAutoresizingMaskIntoConstraints = false
// give it explicit height (or use intrinsic height)
view.heightAnchor.constraint(equalToConstant: 50).isActive = true
view.backgroundColor = .orange
// intertwin it with spaces
if index < spaces.count {
stack.addArrangedSubview(spaces[index])
spaces[index].translatesAutoresizingMaskIntoConstraints = false
}
}
// constraints for 1 4 1 proportions
NSLayoutConstraint.activate([
spaces[1].heightAnchor.constraint(equalTo: spaces[0].heightAnchor, multiplier: 4),
spaces[2].heightAnchor.constraint(equalTo: spaces[0].heightAnchor, multiplier: 1),
])
let stretchConstraint = spaces[0].heightAnchor.constraint(equalToConstant: 1000)
stretchConstraint.priority = UILayoutPriority(rawValue: 1)
stretchConstraint.isActive = true
}
}